British pop star Tulisa Contostavlos has opened up about her heartache and disappointment after a sex tape she made with an ex-boyfriend emerged online.

Contostavlos, who is a judge on Britain's The X Factor, ordered her lawyers to fire off a round of cease and desist letters this week after a website uploaded a seven-minute clip of a blonde woman purported to be the star performing a sex act.

Her legal team vehemently denied Contostavlos was the girl in the footage, declaring, "This tape is 100 per cent fake and is just someone trying to cash in on her X Factor role. She is horrified that someone would go to the extreme lengths of fabricating a video. It is absolutely not her. Tulisa has categorically never allowed anyone to film her having sex."

However, the singer has now released a video message via Twitter.com to sensationally confirm it is her in the tape, and blame her former lover Justin Edwards for allegedly exposing the footage.

In the video, she says, "I wanted to set the record straight on a certain tape circulating online that consists of footage of me and my ex-boyfriend having an intimate moment. I have never been the type to sit down and keep my mouth shut, and to keep quiet about anything, especially when I've done nothing wrong whatsoever."

"Six months ago, I got a call from a mutual friend saying that apparently he has footage of me, that he's been threatening to bring it out to ruin my career. I confronted him, he lied about it. And here we are today and the footage is now circulating online."

"As you can imagine, I am devastated, heartbroken. When you share an intimate moment with someone that you love and care about and trust, you never imagine that footage will be shared with the world.

"I don't feel that I should be the one to take heat or stick (abuse). This is something that he took upon himself to put online. He's now sitting in silence, saying it's not him on the tape, when it is.

"I have been deeply betrayed by him. This is something I've had to deal with, there's nothing I can do about it, but I do feel that I should share my side of the story."

Slideshow: Sexy Tulisa Contostavlos Photos