NEW YORK – A CBS News employee is accused of trying to extort $2 million from David Letterman, forcing the late-night host to admit in an extraordinary monologue before millions of viewers that he had sexual relationships with female employees.

Letterman said that "this whole thing has been quite scary." But he mixed in jokes while outlining what had happened to him, seeming to confuse a laughing audience at Thursday's taping about whether the story was true.

The network said the person who was arrested works on the true-crime show "48 Hours" and has been suspended. A person with knowledge of the investigation said the suspect is Robert J. Halderman. The person spoke on condition of anonymity because authorities have not released the suspect's name.

A "48 Hours" producer named Joe Halderman was part of a team nominated for an Emmy for outstanding continuing coverage of a news story in a news magazine in 2008. Two numbers listed for Halderman were disconnected, and a message left at a third number was not immediately returned Thursday.

The Manhattan district attorney has scheduled a news conference for late Friday morning to talk about the arrested employee, who the DA says is from Connecticut

Three weeks ago, Letterman said, he got in his car early in the morning and found a package with a letter saying, "I know that you do some terrible, terrible things and that I can prove that you do some terrible things." He acknowledged the letter contained proof.

He said it was terrifying "because there's something insidious about (it). Is he standing down there? Is he hiding under the car? Am I going to get a tap on the shoulder?"

Letterman said he called his lawyer to set up a meeting with the man, who threatened to write a screenplay and a book about Letterman unless he was given money. There were two subsequent meetings, with the man given a phony $2 million check at the last one. Letterman joked it was like the giant ceremonial check given to winners of golf tournaments.

He told the audience that he had to testify before a grand jury on Thursday.

"I was worried for myself, I was worried for my family," he said. "I felt menaced by this, and I had to tell them all of the creepy things that I had done."

He said "the creepy stuff was that I have had sex with women who work for me on this show. My response to that is yes, I have. Would it be embarrassing if it were made public? Yes, it would, especially for the women."

Whether they wanted to make the relationships public was up to them, he said.

"It's been a very bizarre experience," he said. "I felt like I needed to protect these people. I need to protect my family. I need to protect myself. Hope to protect my job."

CBS said in a statement that "we believe his comments speak for themselves."

Perhaps as a defense mechanism, Letterman sprinkled his remarks with jokes: "I know what you're saying," he said. "I'll be darned, Dave had sex."

He said he wouldn't talk further about it, and recited a Top Ten list. But it wasn't far from his mind. During banter with actor guest Woody Harrelson, Letterman said, "I've got my own problems