Kurt Cobain's death rocked the world in 1994, but for some the verdict of suicide has simply never sat right for many.
Almost 30 years after the shocking news, a best-selling author is adamant he has the proof to finally show the icon was murdered.
Ian Halperin has studied the case for decades and is ready to reveal his findings with the world - including reports he says shows the singer had "70 times the lethal dose of heroin in his system" when he was found with a gunshot wound to the head in Seattle in April 1994.
Canadian-born Halperin claims it would have been "scientifically impossible" for the star to have been able to even lift the gun, let alone pull the trigger for the fatal blow.
But even before Kurt's death, Halperin claims evidence shows the suicide note found at the scene wasn't actually penned by the star.
Speaking to The Mirror, Halperin said he has had the note scrutinised by two top handwriting experts who both indicated the musician wasn't the penman behind it.
"They [the experts] said the last five lines of the notes was the only part of the note to deal with suicide, but it wasn't in Kurt’s handwriting," he claimed.
"Even her [Courtney Love's] own entertainment attorney says she didn't believe Kurt Cobain wrote a suicide note. That's like powerful."
It wasn't just the note or cause of death that Halperin is questioning, either. The author also threw suspicion at the coroner who provided the final verdict of suicide.
Saying he is the only person to have interviewed Dr Nikolas Hartshorne on camera, Halperin continued: "So I went to his office, and I was stunned because there were Nirvana and Courtney Love posters all over his office, which I thought was bizarre.
"And then he admitted he did have a conflict of interest. He insinuated that he had dated Courtney in the past. And I said 'you know, that is a bit strange, Dr Hartshorne. Shouldn't you have recused yourself from such a high profile case for conflict of interest?'"
Halperin claimed the doctor, who died in a base-jumping accident in 2002, did admit that maybe he should have recused himself from the case, saying the coroner had said he was maybe "presumptuous" in the verdict.
The author reiterates he is not accusing anyone of murder in his new book titled Case Closed: The Cobain Murder: The Killing And Cover Up of Kurt Cobain, but makes it clear he thinks he has "definitely proven it wasn't suicide".
He says the main reason behind his book, other than getting the original verdict overturned, is to stop the copycat suicides that have followed since Kurt's death.
"My goal is just to deter the youth from further copycat suicides, but I do lay out the evidence, proving conclusively it wasn't a suicide. It was definitely murder foul play."
The Mirror has reached out to Courtney's representatives for comment.
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