Heath Ledger’s dad recalled the final conversation with his son on the night before he died

Heath Ledger's dad has recalled the final conversation he had with his son before he died, admitting the tragedy came as a 'surprise' to the family.

Ledger died on 22 January 2008 at the age of 28 of acute intoxication believed to have been caused by an accidental overdose of prescribed medication.

It came at a time when The Dark Knight was in the final stages of production, with his performance as the Joker seen as one of the best ever by film fanatics.

Ledger was awarded the Best Supporting Actor Oscar, with his father Kim accepting the award on his behalf.

Kim told Australia's ABC News eight years ago how the family had been left in 'terrible' shock following the actor's passing.

Ledger had been given the medication to help him sleep as he had long been struggling to nod off.

Heath Ledger died in 2008 (Bob Riha Jr/WireImage)

Kate, Ledger's sister, had spoken to her brother the evening before he passed away, warning him about the dangers of mixing drugs, according to Kim.

Kim recalled: "I guess the whole thing was such a surprise to us. We knew that he was taking some prescription medication for an illness that he had, and my daughter Kate was talking to him literally the night before."

In a separate interview with news.com.au, Kim stated his son made the mistake of mixing the wrong drugs.

He said: "It was a one-off thing. That’s what killed us, because he was warned by his sister the night before: ‘You shouldn’t mix what you’re taking for pnemonia with your ambien’. But most of Heath’s problems were self-induced.

"He was a young guy that travelled all the time for work. Even as a two-year-old, he hardly ever slept. He was trying to work and travel and do everything in a short space of time."

Kim Ledger recalled the final conversation he had with his son (John Sciulli/Getty Images for G'Day USA)

The final conversation Kim had with his son was truly heartbreaking, as he recalled his son's final moments with ABC News: "It was daytime here in Perth and nighttime there in New York, and basically Heath was complaining about not being able to sleep because he was busy, meeting Steven Spielberg the next morning.

“He really needed to be bright and shiny and it was finding it difficult with the chest cold, or the chest infection, to sleep.

“So Kate was saying to him, ‘Well, Heath, you can’t take sleeping tablets on top of prescription medication - you know, it’s not a good mixture.’

“And he sort of said, ‘Katie, Katie, look, it’ll be fine. I just need to get some sleep.’

“Well they are really the last words we ever heard from Heath - or at least the last words that Kate heard.”