Video: Alleged Tulisa Contostavlos sex tape emerges online

The video appeared initially on a site called nottulisa.com which sarcastically stated several times that the girl in the video was not Tulisa.

However fans of the now defunct N-Dubz group are convinced it's her.

"It's definitely her," says one commenter. "It's not like it a dark room or anything, you can see her face. It's her for sure."

The site on which the video first appeared has been taken down however a cached version of the site said: "This crystal-clear movie is in no way is a hidden camera! Just look at Not Tulisa playing to the camera, smiling and laughing... the naughty little minx!

"The fact it is filmed in a PUBLIC PLACE makes the whole sex act even more risky, as anyone could have been watching or taking pictures. Not Tulisa is known for her bad girl background and we are sure this finally shows her how her fans want to see her: Raw and Risky with a bad-ass sex appeal."

Tulisa publicly addressed rumours of a sex tape in August last year, saying that she had never been filmed during the sex act.

Some fans, who appear to accept the girl in the video to be Tulisa, are more sanguine in their comments:

"Frank Lampard, Kim Kardashian, Paris Hilton, Keeley Hazell, Tulisa's just another name on the list.

"They've all done well. KK made a ***king career out of it.

"I think she looks hot."

Update - Tulisa's management have denied that the girl in the video is the singer.