I've let people down. I'm truly sorry. I feel like I have let a lot of people down and for that I'm truly sorry. I want to thank my wife, family and closest friends through this really difficult time.
"I have spoken out because I think it is important that people ask for help if they are going through a rough time and get the proper treatment to help their recovery."
MailOnline has contacted a representative for Ant for comment.
He has been battling his condition for two years after an operation on his knee went wrong, leaving him in constant pain. Following his knee operation he began taking the opioid painkiller Tramadol and became addicted.
It was said people close to him had become concerned that Ant was combining the drug with alcohol, worsening the effects. A friend said: 'He began abusing substances when he was drunk."
Ant underwent further knee surgery at Chelsea and Westminster Hospital in London last Tuesday and is expected to be in a wheelchair for weeks. Doctors had feared his knee could collapse, leaving him crippled. It is not known where he is undergoing his rehabilitation.
In a candid interview in 2013, Ant confirmed he and Dec had 'dabbled' in drugs, as he told The Guardian's Weekend magazine: "Years ago, yeah (we tried drugs), but we're not really druggy people, that's the thing.
"I think you either go into that crowd as a kid or you don't, and we didn't. We found the love of alcohol very early on and we stayed with it."
Dec added: "There's a real pub culture where we're from in Newcastle, so we're just more boozy people."
In February, in an interview with Fabulous Magazine, Ant - who previously spoken about his fertility struggles - revealed he would be "over the moon" to become a dad.
The star, who has been married to Lisa since 2006, couldn't resist gushing about his other half, stating: "I think I'm lucky. Lisa works in the industry and understands it. She's constantly working - sometimes more than me!"
Speaking about the next stage of his relationship, the Newcastle born star confessed: 'We would love to have a family so fingers crossed. If we're blessed with children, then we'd be over the moon!'
In 2013, Ant discussed how he and his make-up artist wife were finding it difficult to conceive. At the time he confessed to Radio Times: "Lisa and I would love to have kids.
We're trying. It's tougher than you think when you get a bit older."
Explaining the issue in terms of his friendship with Dec, Ant revealed: "There's a rumour that we do everything together and I'm holding off having kids till Dec finds himself Mrs Right. I love that idea, but I'm afraid it's not true."
Ant and Dec are close friends and regular visitors to pubs near their multi-million-pound homes in Chiswick, West London.
For a long time Ant managed to hide his problems from those around him, but there had been concern among people who worked with him on the recent finals of BGT about his condition. It was Dec, 41, who urged his friend to get help.
Ant came to stardom on the children's TV show Byker Grove playing the role of PJ opposite Dec, where the pair become best friends on and off set.
They were catapulted into the charts and scored a series of hit songs as PJ & Duncan AKA and the pair have hosted a series of programmes including Pop Idol and Ant and Dec's Saturday Night Takeaway.
Ant, who has amassed a $105 million fortune, signed a two-and-a-half-year contract with ITV in 2007, worth around $53 million, with co-host Dec, launching them into the premier league of British television earners.
