There is no way to verify the FBI's information. It is not clear whether the agents involved were transcribing the true reality of King's private life, or creating idle gossip as part of their campaign against him.

Alongside the tapes was the now-infamous, anonymous letter urging King to avoid embarrassment, with the words, "There is only one thing left for you to do. You know what it is. ... There is but one way out for you." It was delivered inside a manila envelope.

The letter runs to more than 500 words, and claims to be from an African-American who supported the civil rights movement. In fact, it was written by the FBI.