Stephanie Birkitt: Banned From Late Show Set

Stephanie Birkitt, the woman at the center of the David Letterman sex and blackmail scandal, has been banned from New York City's Ed Sullivan Theater.

The 34-year-old former aide, who appeared on the Late Show numerous times in comedy bits, was later offered a job by Dave as his personal attorney.

She and Letterman had a sexual affair of indeterminate length.

It was Robert Halderman - the ex-boyfriend of Stephanie Birkitt - who found out about the pair's secret relationship and then allegedly threatened to release the scandalous information unless Letterman forked over $2 million.

Halderman has been arrested for this crime but is free on bail.

CBS is aware of Stephanie Birkitt's ban from David Letterman's set.

Birkitt, who was allegedly cheating on Robert "Joe" Halderman - Letterman's accused extortionist - with the Late Show host, wrote all about it in her private diary.

She also wrote Dave some "trashy" love letters that will embarrass them both if and when they become public, according to a report in the New York Daily News.

While David Letterman's wife, Regina Lasko, was not married to him until earlier this year, the two have a son, born in 2004, and had been together for 20 years.

Letterman apologized on air to Regina and his staff Monday night.