Cobain died on 5 April 1994, aged 27, from what authorities described as a self-inflicted gunshot wound from a Remington Model 11 20-gauge shotgun, with his death being ruled a suicide at the time.

However, now, as per a report by The Daily Mail, an unofficial team of private sector forensic scientists has published a peer-reviewed paper in the International Journal of Forensic Science contesting earlier findings, and claiming that one or more assailants confronted Cobain, and made his death look like a suicide.

The paper argues that Cobain's assailants forced a heroin overdose to incapacitate the Nirvana singer, before shooting him in the head and placing the shotgun in his arms, along with a forged suicide note.

The new piece of research, presented by forensic scientists who previously worked on cases related to gunshot trauma, points to ten points of evidence for Cobain's alleged homicide.

Kurt Cobain's death: A re-examination

According to the autopsy report by King County authorities viewed by The Daily Mail, Cobain's body was on the floor of the greenhouse above his garage.

"Examination of the miscellaneous papers in the left front pocket [of Cobain's jeans] reveals some writing in black ink, reading 'Remington 20 gauge 2-3/4 shells or shorter setup light shot 10888925'," the 20 June 1994 autopsy reads.

This in itself is suspicious, independent researcher Michelle Wilkins, who worked on the present study, told The Daily Mail.

"To me, it looks like someone staged a movie and wanted you to be absolutely certain this was a suicide. The receipt for the gun is in his pocket. The receipt for the shells is in his pocket. The shells are lined up at his feet," Wilkins explained.

Forensic evidence reviewed by the researchers also revealed that Cobain's sleeves were rolled back, and his heroin kit was found several feet away, containing capped syringes, cotton buds, and pieces of black heroin of roughly equal size.

"We're supposed to believe he capped the needles and put everything back in order after shooting up three times, because that's what someone does while they're dying," Wilkins told The Daily Mail.

"Suicides are messy, and this was a very clean scene," she added.

Cobain's autopsy also reported finding fluid in the lungs, bleeding in the eyes, and damage to his brain and liver, which, as per the new research, are unusual for a quick gunshot-inflicted death. Rather, they are common in deaths from heroin overdoses that cause slow breathing and low blood flow.

Given that Cobain suffered eye bleeding and organ damage, the researchers argue that his body may have been starved of oxygen, which most likely did not happen from the gunshot wound alone.

In most head gunshot deaths, blood is often drawn into the airways, but Cobain's autopsy did not mention this, the new report found.

"He's dying of an overdose, and so he can barely breathe; his blood isn't pumping very much. So that means the brain and liver aren't getting oxygen, and they're starving, and they're dying," Wilkins told The Mail.

Wilkins further explained that the size and mechanics of the shotgun used for the purported suicide made it improbable that a comatose, overdosed Cobain could have used it.

"If you look at the crime scene photos, you can see how big that gun is. Imagine he's comatose and dying, and also the way that he would have had to hold it… it's six pounds," Wilkins said.

The autopsy report also found that Cobain's left hand was tightly wrapped around the muzzle end of the gun's barrel, yet the shotgun shell was found on top of a pile of clothes opposite the expected ejection direction.

To test whether such a scenario was plausible, the team replicated the weapon used and found that the gun would not have ejected a shell at all if one's hand was on the forward barrel, where Cobain's hand was reported to be.

"If you ever look at photos of shotgun suicides, they are brutal. There is no universe where that hand is not covered in blood. You could eat off of… well, I mean, gross, but, like, his hand is so clean," Wilkins was quoted as saying.

The researchers also noted that blood patterns found at the crime scene suggest his body was moved -- "There's also blood on the bottom of his shirt. The only way the blood would get on his shirt is if Kurt was lifted and his head was down."

Further, Cobain's alleged suicide note was also found to be odd, with researchers noting that there was nothing about suicide in it, except four lines at the bottom, which look different from the rest of the handwritten note -- "Then there are four lines at the bottom. If you even look at the note, you can see that the last four lines are written in different… the text is a little bit different. It's bigger, it's… looks more scrawly."

The homicide scenario, the researchers posit, explains these discrepancies better, suggesting that Cobain's left hand was placed on the weapon after his death.

What happens next?

That said, the researchers explained that they weren't looking for fresh arrests at this moment, but rather for a re-examination of evidence and the conclusion drawn, which may well happen.

"King County Medical Examiner's Office worked with the local law enforcement agency, conducted a full autopsy, and followed all of its procedures in coming to the determination of the manner of death as a suicide," a spokesperson for the office told The Mail.

"Our office is always open to revisiting its conclusions if new evidence comes to light, but we've seen nothing to date that would warrant re-opening of this case and our previous determination of death," the person added.

The Seattle Police Department (SPD), however, is unlikely to reopen the case at this moment and has stuck by the conclusion of its investigators in the case.