When Oscar-winning actor Heath Ledger, star of The Dark Knight and Brokeback Mountain, died from an accidental drug overdose in 2008, his father Kim Ledger was certain that what happened was "part of a massive picture."
It was determined that Heath Ledger had ingested a fatal combination of sleeping pills with opioids, dying in his sleep.
This has motivated Mr Ledger to speak out against prescription drugs, and he will be coming to New Zealand to campaign against the misuse of them.
"I came to the understanding that something absolutely positive needs to come out of this," his father said.
Scriptwise, the Australian group of which Kim Ledger is a patron of, was formed to help prevent the misuse of prescription medication. They aim to raise awareness about the seriousness of the issue.
Mr Ledger will be speaking at the Cutting Edge Addictions Conference in Rotorua in September.
His message will be "what can start off as a simple prescription can result in medication misuse and people tend to get on to a treadmill that they struggle to get off."
Speaking with The Daily Mail Australia, Mr Ledger said that the death of his son during post-production on The Dark Knight - for which he won a number of posthumous awards - was his own fault: "It was totally his fault. It was no one else's - he reached for. He put them in his system."
He did, however, note that the demands of being a top actor would have meant his son needed prescription drugs to keep up with his international schedule.
It's not unusual for prescription medication to be the causal factor in celebrity deaths - pop superstar Prince died earlier this year from an accidental overdose of fentanyl, and Michael Jackson died of acute toxicity from an anaesthetic in 2009.