Twenty years ago, a shotgun blast killed Nirvana frontman Kurt Cobain. That much remains undisputed. But even though officials insist that shot was self-inflicted, a small but prolific group of conspiracy theorists believes foul play was involved. Now, the purported mysterious circumstances surrounding Cobain's death are at the heart of the new docudrama "Soaked in Bleach."

As depicted in the "Soaked in Bleach" trailer premiere above, one of the main proponents of the latter theory is Tom Grant, a former police detective-turned-private investigator hired by Cobain's wife, Courtney Love. In the days before Cobain's body was discovered on April 8, 1994, Love hired Grant to locate her missing husband.

[Related: Nirvana's Top 10 Songs, 20 Years After Cobain's Death]

Grant soon realized the story "just didn't add up," as he says in the trailer. "This woman's husband had just been found dead, and there didn't seem to be any sadness whatsoever. And there was more to this than what I was being told."

Grant discovered so many "red flags" — alleged time discrepancies involved in the investigation, disturbing phone recordings from Love, inconsistencies in Cobain's suicide note — that the man Love hired to find her husband ultimately ended up accusing her of foul play, which she has denied over the years.

The name of the film is a reference to the second verse of Nirvana's "Come as You Are," written by Cobain: "Come doused in mud, soaked in bleach, as I want you to be." Like many of Cobain's lyrics, the meaning is ripe for interpretation. But if read in the context of the film, it would seem to imply that the truth of Cobain's messy death has been bleached by a cover-up.

Of course there's another ambiguous lyric in the song: "When I swear that I don't have a gun/No, I don't have a gun." A lyric that becomes all the more mysterious given the accusations set forth in "Soaked in Bleach."

"Soaked in Bleach" will be debuting at film festivals soon.

Hear Nirvana's "Come as You Are":