A top TV producer was charged Friday with attempting to blackmail talk show star David Letterman for having sex with female staffers in a case rocking the US television world.

Joe Halderman, an Emmy Award-winning producer for CBS's real-life crime show ''48 Hours'', pleaded not guilty in New York to a grand larceny charge.

The indictment followed Letterman's stunning revelation of the alleged blackmail plot -- and his affairs with co-workers at CBS -- during his nationally broadcast talkshow late Thursday recorded before a live audience.

Details of the plot sounded like a mixture of the kind of gossip and crime scenes that Letterman, 62, and Halderman, 51, have spent years bringing to television viewers.

Manhattan District Attorney Robert Morgenthau told a press conference that Halderman waited outside Letterman's Manhattan home at 6:00 am on September 9.

He allegedly demanded the talkshow host to pay ''a large chunk of money'' for a screenplay treatment Halderman said he had written.

The attorney handed over a two-million-dollar check

When Letterman looked, he found the document was in fact a chilling note referring to his professional success and "beautiful loving son," then warning that his ''world is about to collapse about him'', Morgenthau said. Letterman was given two hours to respond.

Letterman's lawyer met with Halderman at a midtown Manhattan hotel where he was told to come up with two million dollars in exchange for silence over Letterman's dalliances with staff, the prosecutor said.

Two more meetings took place between the lawyer and the blackmailer during which the attorney wore a hidden recording device.

On Wednesday, the attorney handed over a two-million-dollar check -- faked by the authorities -- that Halderman allegedly deposited a day later.

I have had sex with women who work on this show

David Letterman

In his on-air mea culpa, Letterman described finding the threatening package in the back seat of his car.

Letterman: I have had sex with women who work on this show 

The package, said the TV star, contained ''stuff to prove I do terrible things.''

Letterman then apparently sought to preempt further fallout within CBS and from his audience by offering a confession.

- I have had sex with women who work on this show - Letterman admitted, prompting confusion from members of the studio audience who were hoping for the punchline that never came.

At turns appearing nervous and flippant, Letterman described how he went to the authorities to report the blackmail.

"This morning, I did something that I have never done in my life, and it was a combination of just unusual and scary, this whole thing has been quite scary," he said, "I had to go downtown to testify before the grand jury.

Letterman was afraid of embarrassing the women with whom he had relations

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

Letterman said he was afraid of embarrassing the women with whom he had relations, but was forced to act.

"What you don't want is a guy saying 'I know you had sex with women, so I would like two million dollars or I'm going to make trouble for you,' so that is where we stand right now," explained Letterman.

The "Late Show with David Letterman" made its debut in August 1993, and has since received a stream of famous and infamous guests, winning six Emmy Awards in the process.

A doyen of the nightly talkshows, he earlier this month hosted US President Barack Obama, the first time a sitting president appeared on the CBS show.