Joan Rivers death threats were revealed as FBI files detailed a stalker's messages that were sent to the late "Fashion Police" host.

According to a report from Radar Online, a fanatical Anti-Semitic bigot who called himself "Mr. Clean" sent Joan Rivers death threats back in 1991.

"I'm watching... your every move," the stalker warned the "Fashion Police" star in a letter mailed more than 20 years ago.

"I shall go down in history as the person who found this movement. I am on a crusade to clean the world of the 2 biggest Jew money making promoters of Homo-sexuality on television and radio."

"This movement is crucial for the world's survival, that it must be started immediately," the disturbed fanatic said.

The note was labelled for "Queen Joan Rivers." It was also addressed to a second, unidentified media contact.

The said Joan Rivers death threat was sent to a popular New York City radio station and had the postmark of Brooklyn, New York.

"Just to let you know that I purchased a piece of exterminating equipment It is big and powerful. It will be messy, but pain free almost," the stalker told Joan Rivers.

"If I don't see you by the Jew New Year. I promise you it will be soon after."

The person who sent the 1991 Joan Rivers death threats was never identified by the FBI.

An earlier report from thehill.com said the "Fashion Police" host received disturbing messages as early as in 1973. The first Joan Rivers death threat was reportedly caused by a joke that she made about Polish culture.

"Perhaps ... I can teach you the difference between a joke and an assault on human dignity and decency," the stalker said via a Western Union telegram.

"My people will no longer sit back supinely while a human cesspool spews her dirt on them. And for a Jewess you should know better."