A graphic anonymous letter the Federal Bureau of Investigation sent to Martin Luther King in an apparent attempt to get him to take his own life has been published in full for the first time.

Known as the “suicide letter,” the FBI had heavily censored the document, keeping its colorful language a closely guarded secret. However, a historian at Yale University found an unredacted copy in the National Archive while conducting research on FBI chief J. Edgar Hoover, according to the Telegraph.

The letter was written in 1964 by a deputy of Hoover, who was posing as an angry civil right activist, and looks to be a bald-faced attempt to get the civil rights leader to blackmail the pastor into taking his own life.

Calling King a “filthy animal,” the letter raves against him using sexual slurs three years before his assassination. The FBI included cassette recorders of King’s extramarital affairs, which the bureau had gained by bugging his homes and hotel rooms where he stayed.

“You will find on the record for all time your filthy, dirty, evil companions, male and females giving expression with you to your hidious [sic] abnormalities,” the letter states. “It is all there on the record, your sexual orgies. Listen to yourself you filthy, abnormal animal.”

“You are on the record. You have been on the record – all your adulterous acts, your sexual orgies extending far into the past,” the letter continues. “This one is but a tiny sample. You will understand this. Yes, from your various evil playmates on the east coast to [name redacted] and others on the west coast and outside the country, you are on the record. King you are done.”

The newly unearthed letter revealed one passage the FBI decided to scrub from its version: a section that compares King to Henry VII states that “…and his countless acts of adultery and immoral conduct lower than that of a beast.”

The letter urges King to kill himself, referencing 34 days, which was to be the date that King accepted the Nobel Peace Price in Sweden. The FBI apparently hoped that the fear of having his extramarital affairs exposed would be enough to cause King’s suicide, stating in the letter that “there is but one way out for you” and that “you better take it before your filthy abnormal fraudulent self is bared to the nation.”

King’s wife Coretta was the one who read the letter first. King himself did not read it until he returned, and then showed it to his advisers who agreed that it was obviously from the FBI.

It is believed Hoover lashed out at King for comments he made that the FBI had failed to protect black people in the South. Hoover had already attempted to get newspapers to run with the recordings without success, and used this as a last-ditch effort to get at King.