It's been reported that his wife Lonnie will act as executor of his will, while his former wives, children and even his brother could join the fight over his legacy and earnings.
Ali earned his biggest payday inside the ring on October 10, 1980 against Larry Holmes. Despite falling by a technical knockout to Holmes, he earned $8million, according to the Los Angeles Times.
In one of his most famous bouts called the 'Thrilla in Manila,' the icon earned $6million in the ring against Joe Frazier in 1975.
That payday came about roughly one year after he defeated George Foreman in Zaire, now the Democratic Republic of the Congo, for 'The Rumble in the Jungle.'
Ali took home about $5.45million in that 1974 match.
The three-time heavyweight champ earned millions of dollars in revenue each year through his company, GOAT LLC, until he sold it, but retained 20 percent interest of the business.
The company's title was an acronym for his trademark phrase, 'Greatest of All Time.'
According to Forbes, his name had generated between $4million and $7million annually from roughly 2001 to 2006, through deals with companies like Electronic Arts and Adidas.
In addition, Ali and his wife Lonnie owned property in Arizona and Kentucky, and last year they sold a home located outside of Philadelphia for $690,000 that he lived in to train for some of his most dramatic fights.
Furthermore, it's unknown what type of memorabilia the legend has that could potentially be sold for millions of dollars by his family.
It's highly unlikely that Ali didn't leave behind a will that includes his wife and children, as he battled Parkinson's Disease for over 30 years until his death on June 3.
'After a 32-year battle with Parkinson's disease, Muhammad Ali, has passed away at the age of 74. The three-time World Heavyweight Champion boxer died this evening,' Ali's spokesman said.
Ali's family said his funeral would be held in his hometown of Louisville, Kentucky, and thanked the public for their outpouring of support.
Ali, who was also a key figure in America's civil rights movement, had been on life support in hospital, after he was found 'barely breathing' at his home on Thursday.
He was taken to hospital with an 'unshakable cough', a separate source said, with his fatal respiratory problems likely to have been complicated by his Parkinson's disease.
The Greatest was surrounded by his family, who rushed to be at his bedside on Thursday and Friday after doctors warned his condition was 'rapidly deteriorating', a source said.
Daughter Hana paid tribute to her father on Twitter and Instagram today, writing: 'Our father was a 'Humble Mountain!' And now he has gone home to God. Pray for the peace of his beautiful soul and for the happiness of his further journey. God bless you daddy. YOU ARE THE LOVE OF MY LIFE!'
It was earlier reported that Ali's family had started making funeral arrangements after doctors warned that he was just hours from death.
Ali's spokesman Bob Gunnell told MSNBC that the family were 'devastated' by his death.
'Muhammad passed with his family at his side just moments ago,' he said.
'It was a very peaceful passing and they are with him as we speak. You know, we lost a great person in this world tonight.
'We don't have an official cause of death yet, but it has to be from complications of Parkinson's.'
Gunnell said on Thursday that the boxer was being treated for a respiratory issue at a hospital, which he confirmed again on Friday morning.
Tributes have flooded in from around the world, with friends and fellow fighters paying Ali, who was voted Sports Personality of the Century, the highest accolades.
