Courtney Love arrives at the International Press Academy Satellite Awards in California on February 23, 2014.

Courtney Love in 2014. Photo: Getty

Courtney Love's father claims he can prove his daughter was linked to the death of her husband Kurt Cobain. And he'll tell you about in his book, which he is currently promoting.

Twenty years after the musician's death a newly surfaced note, penned by Cobain, has Hank Harrison convinced his rock-star daughter killed Cobain.

The undated note, released on Wednesday, was collected as evidence into the investigation of Cobain's death in April 1994, which was ruled a suicide.

Kurt Cobain arrives with wife Courtney Love, holding their daughter Frances Bean Cobain, for the MTV Music Awards show in Los Angeles in this September 9 1992.

Kurt Cobain with wife Courtney Love and daughter Frances Bean Cobain at the MTV Music Awards show in 1992. Photo: Fred Prouser

Harrison, who is estranged from his daughter, told RadarOnline: "No doubt she was capable. I can't prove she pulled the trigger, but I can prove her involvement to a high degree of certainty."

Harrison and Courtney's mother, Linda Carroll, were said to be experimenting with LSD when Courtney was born, reports the Daily Mail. The pair soon split and Love never became close with her father.

In anticipation for the 20th anniversary of Cobain's death, the Seattle Police Department reviewed internal files regarding the front man's death.

The department also released never-before-seen photos from the crime scene and a detective's full report on the re-examination of the suicide file.

The photos released had remained undeveloped until recently and contained shots of Cobain's suicide note in its original location. There's also a close-up shot of Cobain's wallet where his face is clearly visible on a driver's licence.

CBS News reports, among the suicide file were hundreds of pages of police reports and evidence recovered, including the hand-written note.

The note says: “Do you Kurt Cobain take Courtney Michelle Love to be your lawful shredded wife. Even when she's a b**ch with zits and siphoning all [your] money for doping and whoring.”

The tone of the note is open to interpretation, but Harrison has used it to weigh in with his. “If you read the true meaning of this small note, and place it in conjunction with the rest of the evidence, anyone with even half a wit will see that something dire and awful took place,” he told Radar.

Remaining rather vague, the ex-Grateful Dead manager intends to publicise his “proof” in his republished book, Love Kills: The Assassination of Kurt Cobain.

As well as his bizarre claims about Love's apparent involvement, Harrison has questioned the way the Seattle Police Department handled the investigation.

Harrison said: “Nobody, except me, asked the obvious question: 'Why weren't they developed 20 years ago?'”

“They weren't developed because the police had already decided it was a suicide and didn't need any more evidence,” he says.

This isn't the first time Harrison has accused his estranged daughter of involvement in the grunge rock icon's death. In 2004 Harrison told NBC's Dateline that, “She's a psychopath, she has a sociopathic personality like I do.”

Despite conspiracy theories, two decades later investigators still conclude that Cobain died of suicide.

Love has yet to comment on the letter. She is currently promoting her upcoming single release.

Love was married to James Moreland briefly in 1989 and to Cobain in 1992. The pair stayed married until Cobain's death in April 1994.

Cobain and Love had one child together, Frances Bean Cobain. Harrison is banned from seeing her.