Prince took an overdose of painkiller days before his death
Prince was treated for an overdose of the powerful opiate painkiller Percocet six days before his death, after taking the prescription drug for long-term hip problems.
The singer had suffered hip issues for at least a decade, but refused to have surgery because it was incompatible with his beliefs as a Jehovah's Witness.
Following a concert in Atlanta on April 14, he complained that the pain was worse than usual. A private jet taking him home to Minnesota the following day then made an emergency landing in Moline, Illinois.
He was found to have taken significant quantities of Percocet, a popular prescription painkiller known to be addictive. Paramedics at the airport administered a so-called 'save shot', which is used in emergencies to counter serious side-effects such as loss of consciousness.
The report emerged as tributes to the singer poured in from around the world. President Barack Obama, who is currently in London, said he had listened to 'Purple Rain' and 'Delirious' that morning at the US ambassador's residence to get "warmed up" for his meetings. "I loved Prince. It's a remarkable loss," Mr Obama said.
Percocet was one of the many prescription drugs found at the home of Michael Jackson after his death. Actor Heath Ledger also took Percocet among a cocktail of prescription drugs when he suffered a fatal accidental overdose.
Seven years ago a US government advisory panel recommended the drug be banned because of its effects on the liver. The panel said that over time, patients often needed ever higher doses to achieve the same effect.
Following the non-fatal overdose, Prince made four trips to a pharmacy.
His hip problems were believed to be related to exuberant stage performances and wearing high heels. He often walked with a cane. As long ago as 2009 a source close to him said: "He's in a lot of pain. He's popping painkillers and hoping it will all go away."
In recent weeks his health had become a serious concern to friends amid suggestions he was suffering from flu and "walking pneumonia".
The musician held an impromptu party last Saturday night at Paisley Park, his 55,000sq.ft complex in Chanhassen, Minnesota, where he lived and recorded nearly 30 albums.
Cory Amundson (29), a photographer who was in the front row as Prince took to a tiny stage at the party, said: "We knew he'd just been hospitalised so we weren't expecting him to actually show up. But then he popped out. I was a few feet away and he seemed fine to me. It was his way of saying, 'Hi, I'm OK.'"
A post-mortem examination on Prince's body was held yesterday but a spokesman for the local coroner said the results would not be known for days or even weeks.