HOLLYWOOD – Kim Kardashian will have to come up with $30 million if she wants to buy back her sex tape.

A mystery buyer is trying to snap up the rights to the X-rated 39-minute clip of Kim Kardashian having sex, which was filmed in February 2007.

The sex tape features the socialite and her then-boyfriend, R’n'B singer Ray J, romping in a hotel room.

“It’s a wild tape,” says a viewer from Great Britain.  “Ray J. and Kim are awesome together.”

Vivid Entertainment, the firm who currently holds the rights to broadcast it, yesterday revealed they had been approached by a Tennessee law firm representing a potential bidder.

A lawyer’s letter hinted the eager buyer could be directly linked to Kim, who has repeatedly spoken of her shame at featuring in the grubby film.

The letter says: “We would purchase any other footage you may have control of that involves Ms Kardashian.”

Vivid boss Steve Hirsch says he is open to the deal but it will cost dearly.

He said: “Based on its long-term value, it looks like £18million would be a starting point for a discussion on all of the rights.

“I have no idea who is behind this offer but if it’s Kim, I have a tremendous amount of respect for her.

The 30-year-old’s marriage to basketball player Kris Humphries earlier this month sparked a surge in viewings of the clip — which can be accessed online.

More than two million people logged on to watch it in August alone. It normally attracts 300,000 eager eyes a month.

Search engine Google said the Irish were the biggest watchers — paying $60 to view it for a month on the web.

Kim said earlier this year: “There’s embarrassment and shame.”

Here’s Kim waving to the camera in the tape: