David Letterman admits affair on-air and avoids blackmail

In an extraordinary on-air revelation, US chat show host David Letterman has confessed to being the target of a $2million extortion plot over his affairs with female employees on his show.

Shortly after Letterman's admissions last night, it was announced that an employee of CBS's "48 Hours," a documentary show that regularly features true crimes, had been arrested earlier.

Letterman, 62, who recently married his long term partner, Regina Lasko, began by telling his audience on CBS's "Late Show with David Letterman" that he had testified before a grand jury that morning.

He explained he had found a package in his car three weeks ago from a person claiming to have information about his sexual affairs and demanding $2 million to avoid going public.

According to Letterman, the note said: "I know that you do some terrible, terrible things and I can prove that you do these terrible things."

Letterman added: "Sure enough, contained in the package was stuff to prove that I do terrible things."

Amid laughter, applause and exclamations from his increasingly stunned audience, Letterman continued: "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," Letterman said. "Would it be embarrassing if it were made public? Perhaps it would, especially for the women."

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

Watch David Letterman's sex confession

Unable to resist a joke, Letterman told his audience: "I know what you're saying," he said. "I'll be darned, Dave had sex."

Letterman said that after consulting his lawyer, he had arranged to meet the man who said he planned to write a screenplay and a book unless he was paid off. He then went to the Manhattan District Attorney's office. "They said, Whoa, hello, this is blackmail,'" Letterman said.

As part of the investigation, Letterman met the man twice more, at the last meeting handing over a "phony" check for $2 million.

The alleged extortionist was named by showbusiness website TMZ as Robert Halderman, 51, of Norfolk, Connecticut.

CBS said the man had been suspended but refused to comment further.

Letterman's production company said that during his testimony to the grand jury he had admitted affairs with his staff. There was no indication when the affairs took place.

Letterman, who was married once before, is intensely private, and is rarely photographed with his family. He and his wife, who were married in March, have a five year old son and first began a relationship in 1986.

Shortly after his wedding, he acknowledged rumours of his reputation as a ladies man: "I had avoided getting married pretty good for, like, 23 years, and I -- honestly, whether this happened or not -- I secretly felt that men who were married admired me ... like I was the last of the real gunslingers." It is the second time that Letterman has been the target of an extortion plot.

In 2005, Kelly Frank, a former painter on his Montana ranch planned to kidnap Letterman's nanny and son for a $5 million ransom. He is now in prison.

Letterman has been hosting the "Late Show" since 1993 and has been a fixture on late night US television for nearly three decades. Last week American president President Barack Obama appeared on the show.