Tulisa is already taking legal action against her ex-boyfriend Justin Edwards, claiming damages of up to £100,000 for breaches of confidence and privacy.
And now the singer's PR firm Hackford Jones is suing journalism blog Fleet Street Blues over claims they lied about the tape.
Hackford Jones' founder Simon Jones told the Press Gazette that they had never denied the 6 minute clip was Tulisa, and revealed that comments made last August in The Sun concerned another, fake, tape.
Jones told the website: “It was some pretty outlandish claims on the blog. At the end of the day we all work in the media and mistakes are always made, but the point is I'm happy to hold up my hands if I've made a mistake but I'm not happy to be accused of something I haven't done.
“The whole blog was saying basically PRs who lie should be hauled in front of the Leveson Inquiry and there should be some kind of list put together where you should be struck off the PR list if you're found out to be lying,"
He added: "Once that video came to light we’re hardly going to be issuing denials that it was her, it’s clearly her on the sex tape."
Sky News is also at the end of legal action over the fallout over the video, after reportedly claiming that Tulisa had committed perjury when getting an injunction on the clip.
Jones continued: "There’s been so much misreporting around this case which is funny in a way because in this age of Leveson when you think that everyone should be fact checking, even today people are still running stories based on hearsay.
"We very rarely take legal action in our profession. There seems to be so much rubbish written about this Tulisa story that you do get to the point where you think, ‘I’m sorry I have to set the record straight.’”
On Monday a judge ordered for the injunction on the tape, given under privacy grounds, to be extended.