Stephanie Birkitt ( Photos ) David Letterman Affair

During his "Late Show" broadcast on Friday night, David Letterman confessed that he'd had sexual relations with female members of his staff and he had become the victim of an extortion plot because of it.

One of the women involved in the Letterman extortion plot is Stephanie Birkitt, a former assistant to the CBS Late Show host, according to TMZ.

Birkitt, who was featured on the show regularly, lived with alleged blackmailer Robert "Joe" Halderman, who was arrested yesterday.

Halderman, a 51-year-old producer of CBS's 48 Hours, allegedly was in possession of Birkitt's diary, correspondence and photos - which he says incriminated Letterman.

Birkitt is a 1997 graduate of Wake Forest University. She interned at the "Late Show" during spring 1996 and worked for CBS News, 48 Hours and the Late Show.

After a brief stint at 48 Hours - where Halderman worked as a producer - Birkitt got a job on Letterman's show. She has worked there for more than a decade. Her younger brother Johnny is a field producer on ABC's Dancing With the Stars.

According to RadarOnline, Letterman's relationship with Birkitt ended before his girlfriend Regina Lasko had their son Harry in 2003. Letterman married Regina in March, after dating her for 23 years.

Photos of Stephanie Birkitt below. Also check out photos of Regina Lasko and son Harry .