Kris Jenner is facing a sex tape scandal after a man has threatened to leak nude footage of her.

According to reports, the 58-year-old Keeping Up With The Kardashians momager is being blackmailed by a man who claims he has possession of a video of her having sex.

Radar Online reported that this unidentified man is willing to take the video to the press unless he receives money.

"The man has been demanding money from Kris. If he's not paid, he claims, he'll release the tape," the source said. "He called Kris more than one hundred times in the last seven days, from more than 100 different phone numbers - he uses scrambled cell numbers. He called more than 25 times on Sunday alone."

But Kris is shutting down rumors, claiming that there is no tape to begin with and is fed up with the man calling her house and stalking her. The Daily Mail reported that she even stepped up the security at her home.

"At first she thought it was a joke, because she knew it couldn't be real - obviously she would never allow herself to be taped like that! Initially, she just ignored it," the source added.

Kris' daughter, Kim Kardashian, rose to stardom in 2007 after her sex tape with ex-boyfriend Ray J got leaked onto the internet.

Kardashian is now engaged to rapper Kanye West and he has referenced the tape in one of his recent songs, rapping, "My girl a superstar all from a home movie."

Tags: kris jenner Kim Kardashian Keeping Up With The Kardashians