Tom Petty died from an accidental overdose of prescription medicines, his family have revealed on social media.
His wife and daughter, Dana and Adria Petty, released details of the post mortem, carried out by the Los Angeles corner's office, to his Facebook page Friday night.
The former rocker had a combination of prescription medicines in his system the day he died, including opiate derivatives oxycodone and fentanyl. Antidepressants were also found in his system.
Petty died suddenly in October 2017, aged 66. His family say the rocker suffered from severe pain in his hip and used prescription drugs to medicate his condition.
The statement read: "Unfortunately Tom's body suffered from many serious ailments including emphysema, knee problems and most significantly a fractured hip.
"Despite this painful injury he insisted on keeping his commitment to his fans and he toured for 53 dates with a fractured hip and, as he did, it worsened to a more serious injury," they said.
"On the day he died he was informed his hip had graduated to a full on break and it is our feeling that the pain was simply unbearable and was the cause for his overuse of medication. We feel confident that this was, as the coroner found, an unfortunate accident."
They added: "As a family we recognise this report may spark a further discussion on the opioid crisis and we feel that it is a healthy and necessary discussion and we hope in some way this report can save lives."
Fentanyl is the same drug that killed fellow 80s rockstar Prince in April 2016. The highly potent opiate has been blamed on a growing number of overdoses across the United States.
Official US government figures show millennials were almost 20% more likely to die in 2016 than in 2014, mainly due to misuse of prescription drugs.