UPDATE 11:45am Friday: '48 Hours' producer indicted in extortion plot. Arrest made following hotel sting operation. Keep Reading

In a stunningly candid admission during his show on Thursday night, David Letterman admitted that he has had sexual relationships with female employees of his show, and that someone tried to extort him by releasing information about the relationships. A CBS employee has since been arrested for the alleged extortion plot.

During the taping of his CBS late-night show in New York, Letterman discussed receiving a threat to either pay $2 million or risk the relationships being made public.

"In the back seat of my car, there's a package that I don't recognize. What this is is a guy is going to write a screenplay about me and he's going to take all the terrible stuff that he knows about my life and he's going to put it into a movie unless I give him some money," Letterman explained to the audience.