When he died in 2016, Prince left behind a multimillion-dollar fortune - and enough unreleased music that he might outlive us all. But five years later, the battle for his estate and legacy is still not over. As the first full album from Prince's vault is released, Guy Kelly goes behind the scenes to uncover the real Prince and who has his best interests at heart.

Whenever a musical icon dies, the understandable convention is to look squarely backwards. Grief is formalised in obituaries. Back catalogues are hastily reappraised. Above all, there's a sense of reluctant finality: show's over, folks, nothing more to see here. Prince Rogers Nelson - the man known best as Prince but also, variously, as The Artist Formerly Known as Prince, and simply an unpronounceable glyph - never was much for convention.

When he died in April 2016, aged 57, of an accidental overdose at Paisley Park, his Minnesota home, together with a sense of loss fans experienced a peculiar feeling of anticipation.

As music legend had it, Prince kept a vault deep in the bowels of Paisley Park containing hundreds of hours of unreleased recordings and other material. The hope was that it might now be opened. "I've never said this before, but I didn't always give the record companies the best song," he teased in 2014. "There are songs in the vault that no one's ever heard."

The story went that if Prince were to die tomorrow, there was enough in the locker to release an album a year until sometime in the 22nd century. For his final trick, had Prince ensured that he might just live forever? The answer turned out to be far more complicated. Prince left no will. Divorced since the mid-2000s, he also had no living children (with his first wife, dancer Mayte Garcia, he had a son, Amiir, who suffered from a genetic disorder and died at six days old in 1996), and his parents were long dead.

Quite who would inherit his fortune, estimated at anywhere between $US100 million and $US300 million, including the 6000sq m Paisley Park (which also houses recording studios and a sound stage) - and, perhaps most importantly, gain control of that vault - became the subject of a messy and protracted legal battle.

"It was the immediate question: what will happen to it all?" says Matt Thorne, a writer whose exhaustive biography, Prince, was published in 2012. Thorne saw 19 of Prince's 21 gigs at the O2 arena in 2007. "But the priority for people like me has always been getting the music out."

Last week, the first real treasure from the vault, a massively anticipated but never heard album recorded in 2010 called, Welcome 2 America, was released by the Sony label Legacy. Fans like Thorne call it "the missing piece" in Prince's back catalogue. If the Curtis Mayfield-sounding song Born 2 Die, reflecting on issues affecting the black community, is any indication, it ought to fit as well in 2021 as it did a decade ago.

Overall, it's a collection of songs that those who knew, worked with and adored Prince agree he would have wanted heard. "I think we can see pretty clearly that he did want it out. He released an album every year or two, but there is a gap where this would have been, and there isn't an obvious reason why he'd have withheld this," Thorne says.

But it's not the Prince estate's only release in 2021. Needing to monetise, there is also a recent makeup partnership with the beauty brand Urban Decay, which includes a "When Doves Cry" eyeliner pencil and a "Let's Go Crazy" eyeshadow palette. Unlike the album, this is a collection of products that those who knew Prince are ... well, not quite as sure he would have wanted.

And therein lies the problem: if Prince's legacy isn't handled right, will we see fewer album releases, and far more limited-edition eyeliners? The battle for Prince's estate began almost as soon as he was found unresponsive in a Paisley Park lift on 21 April, 2016. He had reportedly been dead for at least six hours. Two years later, a prosecutor would announce that Prince had been taking what he thought was Vicodin (a common prescription painkiller) without realising the pills were counterfeit and laced with the powerful synthetic opioid fentanyl.

As the music world paid tribute, a will was sought. "We've looked under every box lid," one lawyer said. Some people suggested it was buried in the grounds of Paisley Park. Investigators, lawyers and family - including Prince's sister, Tyka Nelson, now 61, who is also a musician, and five surviving half-siblings, Sharon Nelson, Norrine Nelson, John Nelson, Alfred Jackson and Omarr Baker - knew that the alternative was a potentially very long legal process.

That started in May 2016, when a judge, Kevin Eide, asked a packed Minnesota courtroom whether anybody knew of a will. A pin-drop silence. He confirmed the appointment of Bremer Trust, a bank Prince had history with, as special administrator of his estate. The idea that Prince - a man who placed such an emphasis on control that he played all 27 instruments on his 1978 debut album, For You, and compared record contracts to slavery - would forget to write a will staggered some.

Fans, on the other hand, weren't so surprised. "I just don't think he thought he was going to die," Thorne says. "It does seem contradictory, but I can imagine him thinking, 'Well I don't want to think about that today. Or tomorrow'. He probably thought he had another 20 years." Dying intestate (without a will) in Minnesota triggers a legal process of seeking heirs. "In Prince's case, it took them a year to go through all of that, because there were so many claims," says Jerry A McDonald, an estate attorney in Chanhassen, Minnesota, who's based not far from Paisley Park. "The court had to prove that no one was really his wife or child."

In all, about 45 men and women from all over the US claimed to be Prince's relations. Many said they were love children, including one man in a Colorado prison. He had a lot of girlfriends (among them Kim Basinger and Madonna) and a lot of secrets, but Prince is unlikely to have managed to have dozens of offspring the world wasn't aware of. The judge rejected most, while ordering DNA tests to be carried out on some claimants.

Eventually, in May 2017, Prince's six siblings were declared his official heirs. Prince was born in Minneapolis in 1958, his father, John Nelson, was a jazz pianist who performed under the name Prince Rogers, while his mother was Mattie Della Baker, a singer who later became a social worker. Throughout his childhood, a time in which he proved a virtuoso musician on almost any instrument he picked up, his sister Tyka, two years his junior, was the only sibling to grow up with him.

"I'm ambiguous about [the family]. He spoke very warmly of Tyka, and they had some kind of a relationship," says New Yorker contributor Dan Piepenbring, who was one of the last people to speak in-depth with Prince before he died. In early 2016, Piepenbring was summoned to Paisley Park for a meeting about co-writing Prince's never-finished autobiography, The Beautiful Ones. Prince wanted to "seize the narrative of his own life". They would converse, on and off, until his death, including about family.

"The load of half-siblings, frankly, I hadn't heard of until he died. I know they crossed paths in his childhood, but they didn't seem to be on his mind when he was hashing out the meaning of his family."

"Really, I'm normal," Prince once said. "A little highly strung, maybe. But normal. But so much has been written about me and people never know what's right and what's wrong. I'd rather let them stay confused."

Prince had the mystique and dimensions of a fairytale sprite. He was signed at 18 to Warner Bros and his early albums established him as a thrilling talent. By the mid-1980s, after albums like Controversy, 1999, Purple Rain (which alone spent half a year at No 1 on the Billboard 200 chart) and Sign o' The Times, he was the most exciting pop star on the planet.

If his great rival, Michael Jackson, generally outdid him for ticket and record sales, Prince had him on authenticity, musicianship and pure cool. He was meticulous as a live performer but also wildly unpredictable. He'd jump from speaker stacks in towering heels, drop into the splits, sing in both baritone and falsetto, and stun audiences with improvised guitar solos.

"He needed to be the alpha male to get done what he needed to get done . . . If you wanted your own way of doing things, you shouldn't be working for Prince," his former sound engineer Susan Rogers has said. Often he'd perform until 1am, then start a night's studio session. Prince's blurring of binaries (black or white, straight or gay, male or female, pious or heretical) was matched by his enigmatic behaviour.

There is a whole industry of Prince stories that seem utterly absurd but probably aren't. He would propose random table-tennis challenges in the dead of night, and once thrashed Michael Jackson in a match. He carried a briefcase with light-up roller skates in it. He kept dozens of white doves inside his home. He made excellent scrambled eggs. He went door to door, in disguise, proselytising as a Jehovah's Witness. He requested DJs stop their music and played Finding Nemo instead. And he had a seemingly paranormal ability to disappear and reappear in entirely unlikely places. His ambition, he once said, was to "get to a place where no one can find me".

The matter of who would be Prince's heirs was far from the only headache after his death. Paisley Park needed establishing as a tourist attraction, if only to provide revenue to cover increasing legal and tax bills. Some close to Prince, such as his long-time collaborator Sheila E, have said that he was in the process of turning the complex into a museum before he died, and in 2016 control was ceded to Graceland Holdings, the company that runs the Elvis Presley tourist attraction in Memphis, Tennessee.

That move struck fear into locals like McDonald, who worried the unashamedly kitsch trappings of Graceland wouldn't fit in Chanhassen, but "the Elvis people" were restrained. The deal was always intended as a short-term "matter of necessity", according to Piepenbring, and today Paisley Park Enterprises, Prince's company, is back in control. It runs relatively smoothly as a museum and concert venue. Later, in 2017, Bremer Trust was replaced as administrator by Comerica Bank & Trust, which swiftly fell out with the heirs.

In the years since, about 3000 court filings have made the probate-court proceeding one of the most complicated in Minnesota history. "The first year after his death was utter gridlock - there were a lot of shady figures around then," Piepenbring recalls. "There's an air of the imposter that hangs around [the banks], because they were installed by the courts, not Prince, and I think that causes a lot of bad blood among the fans."

One half-sister, Sharon Nelson, an 80-year-old musician and producer who first met Prince in 1973, made a hobby of launching legal complaints against Comerica. "Prince's estate will be bankrupt by the end of the year," she warned in 2019, with what we're discovering is customary hyperbole. "Prince is not resting in peace while this is going on. He's very upset [about] what these people have done to his estate. It's really sad."

It has been reported that the heirs, either collectively or as smaller factions, accused Comerica of wasting money on legal fees, dragging out the process and not paying out fairly among the six of them. They also requested a co-personal representative be appointed to communicate between themselves and the bank, but were split on who that person should be. In the end, the judge disagreed that the representative was needed.

Dividing an estate like Prince's was never going to be easy. First, his physical belongings had to be added up. This meant the US$10 million Paisley Park, its contents, and various other properties, including several in and around Chanhassen and a 1000sq m house on a Caribbean island. A few of the properties were just parcels of land, since Prince had a habit of razing houses after he had lived in them. "They've already sold some [land] around here off for development, around 170 homes being built," says McDonald. "I always thought that if Prince had lived long enough, he'd have torn down Paisley Park, too."

The taxman also came knocking. This year, the Internal Revenue Service (IRS) claimed Comerica had undervalued Prince's estate by 50 per cent, or about US$80 million, triggering a re-evaluation of everything Prince owned.

Then there are the heirs themselves. One half-brother, Alfred Jackson, died aged 66 in 2019, and allegedly bequeathed his estate not to the other siblings but to a dubious Dutch "entertainment consultant" called Raffles van Exel, who has a canny knack for being close to rich celebrities just before their deaths. He became close to Michael Jackson in the mid-noughties and has been accused of selling a photograph of Whitney Houston lying in her coffin to a tabloid.

Hours before his death, Alfred Jackson sold 90 per cent of his Prince estate rights to Primary Wave, an entertainment company that invests in music publishing rights (last December, Stevie Nicks sold an 80 per cent stake in her back catalogue to Primary Wave, reportedly for about US$80 million).

Tyka Nelson has also cut a deal with the company, and it is rumoured some of the other heirs have followed suit. Those sales present another ethical quandary: Prince was so determined to reclaim the rights to his work - "Own your masters, or your masters own you," as he often said - that he once started rerecording his albums in order to have an identical version he owned, in the same way Taylor Swift is currently doing.

As for the vault? It was a literal safe room with a thick metal door, containing shelving units on which CDs, tapes, documents and hard drives were stored in a fairly haphazard order. As well as some 8000 songs and live recordings, there were said to be more than 50 music videos. Established at Paisley Park in the late 1980s, it was housed underground with an anterior room ("The vault" read a sign outside) in which Prince's awards were kept, and was password-protected - supposedly, by the time he died, he'd clean forgotten the code.

Access has now been granted to Troy Carter, a former Spotify executive, and Michael Howe, a former record-label executive and, crucially, a former colleague of Prince's, who was appointed by the estate to oversee the vault's preservation. "I don't have a lot of interaction with the family, but I attend some of what they call the 'heirs' meetings' every couple of weeks," Howe said in 2018."

The vault has now been relocated to Iron Mountain, a climate-controlled facility in Los Angeles. Howe and a team of archivists work full-time sifting through its contents, trying to find order in Prince's chaos. For all that Prince lived in and around Chanhassen for almost 30 years, it's no surprise to learn very few people ever actually saw him. 'He was very much a recluse, but my wife saw him once at a grocery store," says McDonald, cheerfully.

He describes Prince's behaviour as you might an urban fox: "If anyone did see him, it would be at night. We have a store here that is open 24/7, and he would ride his bicycle to that store after midnight and buy stuff." Charming as that image is, it's also a portrait of a deeply lonely figure.

When Piepenbring met him in early 2016, that was what struck him, too. "I didn't really appreciate it at the time, but he was quite isolated. Paisley Park was a compound designed to house a record label, a full sound stage, a wardrobe office . . . and by the time I went there, all of those functions had winnowed away. What you had left was just Prince living there, with this very small group of people around him, who he often seemed to be apart from," he says.

Despite producing about an album a year for most of his adult life, as well as performing endlessly through the noughties (including a Super Bowl half-time show in 2007 still heralded as the greatest of all time) and right up to his death, Prince was struggling in his final years. All those jumps in high heels and mid-solo splits had taken their toll: the cane he adopted in his 50s added to his always-regal manner, but in reality it was orthopaedic, aiding a sore hip.

He was in pain, and medicating heavily, but only those closest to him knew. "Privately, he was bearing an enormous amount of pain, and he made a show of his purity, adamantly against drugs and alcohol, even against profanity [especially since becoming a Jehovah's Witness in 2001]. So the shock came in knowing he was taking all this medication," Piepenbring says. "He would have felt shame, too, I'm sure."

When they spent time together to co-write over a handful of sessions at Paisley Park, and on tour in Australia, Piepenbring had no idea his collaborator was ill. "I'm somewhat embarrassed that I didn't realise, because the signs must have been there," he says. His first impressions were of a dry, funny man, with a surprisingly deep voice and eagerness to make sense of his life. "I was completely caught off-guard [by his death]. And I think part of the reason people approach the estate with such scepticism is that so much of his death feels unresolved."

To this day, we know that days before his death, Prince had been revived by paramedics after becoming unresponsive on a flight; we know he saw a doctor the day before he died; and we know his staff were concerned about his health at the time. But we don't know where he got the counterfeit Vicodin, and the investigation into his death closed in 2018 with no criminal charges. "That wound is still very raw for a lot of people, which makes it hard to proceed with any sort of posthumous legacy, because people want to know what happened.'

But proceed they will, and next with Welcome 2 America, which was in an almost-finished state when Prince mysteriously decided against releasing it in 2010 or 2011. Now that the probate is coming to a close, it's anybody's guess what Howe unearths, and the estate elects to release, next. "The first question is: is this of the calibre that Prince would've deemed suitable for a theoretical release?" Michael Howe has said. "Are we doing his legacy justice by putting this out there? Without exception, that's the most important thing and we have to use our best judgment."

It doesn't seem likely that the makeup partnership was given quite such scrutiny. But dead celebrities are big business: Michael Jackson has earned about $2 billion since his death in 2009. Even in 2016, Prince was ranked fifth in the annual list of top-earning dead celebrities, with estimated earnings of $25 million.

Piepenbring understands why people are wary. "I think in the estate's current incarnation there are a lot of people who knew him in life [like Howe], and although there are occasional things that make me roll my eyes a bit, like the makeup partnership, in terms of the music, they're doing a good, judicious job," he says. "But I think anybody would be nervous. I stood in the vaults, there's such a wealth of material, and it's sort of perpetuating his legacy from beyond the grave. So the more that mystery can be preserved, the more enjoyable it will be. If they're just going to do a bunch of cosmetic and wardrobe deals, then I don't know . . . "

If they do right, and the disputes really do end, the Prince estate could almost make it seem as if he never left us. "Electric word, life. It means forever and that's a mighty long time," Prince sermonised in the introduction to Let's Go Crazy. "But I'm here to tell you there's something else . . . The afterworld." He always was a visionary. The show goes on.

- Telegraph Group Ltd