Credit: Duffy-Marie Arnoult/

When is a sex tape not a sex tape?

When it's a "joke," says Chelsea Handler. On Wednesday, RadarOnline reported that it had acquired a decade-old tape of comedian Handler, now 34.

In the tape, the future Chelsea Lately hostess allegedly appears in her apartment, does a typical stand-up routine before taking off all of her clothes and "engaging in an explicit sex act" with a British-accented male partner, Radar reports.

A rep for Handler tells "It isn't a sex tape. It's a tape that was done for a stand up comedy bit."

And on her show Wednesday night, Handler didn't deny the existence of the tape or dispute its X-rated contents.

Instead, she quipped, "Thanks for ruining my surprise Christmas gift to my staff...It was made as a joke. I put it on an audition tape for a comedy club because I'm a comedian."

Handler added, "I've been showing it at birthday parties for f***ing years!"

She also claims that she received a a $1 million offer to market the tape. "And you know what I said? I'm not worth it."