After Prince, above, had to be revived from a drug overdose a week before his death, one friend told the musical superstar that he needed to stop taking painkillers. But Prince said he couldn’t — his hands hurt so much that if he quit, he’d have to stop performing.

“This piano tour I think was getting to his hands,” singer Judith Hill told investigators, according to a transcript of her interview.

Those words, found amid hundreds of pages of interviews between investigators and Prince’s closest confidants, provide insight into just how much the man known for his energetic performances and larger-than-life personality was suffering.

“How did he hide this so well?” Prince’s closest friend and bodyguard Kirk Johnson said in an interview with detectives. While Johnson said he didn’t realize that opioids were a problem until that overdose, he had noticed Prince was unwell before that and took him to a doctor.

Prince was 57 when he was found unresponsive in an elevator at his Paisley Park studio compound in suburban Minneapolis on April 21, 2016. An autopsy found he died of an accidental overdose of fentanyl, a synthetic opioid 50 times more powerful than heroin.

Johnson and Hill were on Prince’s plane when he overdosed on the way back from an April 14, 2016, concert in Atlanta. Hill said that Prince told her he was depressed, enjoyed sleeping more than usual and was incredibly bored. The plane made an emergency landing in Moline, Ill., and paramedics had to use two doses of a medicine that reverses the effects of an opioid overdose.

— Associated Press