The X Factor star's cousin and N-Dubz bandmate appeared to write in an explicit tweet that he and Fazer have been involved in threesomes.
"JUST SO EVERY 1 KNOWS ME AND FAZER HAVE F...CKED MANY BITCHES 2 GETHER,SO I AM CLEARLY STATING THAT THE D..K IN T'S ALLEGED SEX TAPE IS FAZERS," read the first post.
A separate tweet minutes later added: "SECOND OF ALL, THAT WAS MORE THAN THREE YEARS AGO WHEN FAZER TOOK THEM PICS..THIS IS SIMPLY @IamFazer TRYING 2 GET @officaltulisa BACK! NUFF SAID!"
However, both posts were deleted soon after they went up this evening.
The six-minute 35-second recording was posted on a website named Not Tulisa and later on UK website pappzd.co.uk, before it was removed.
Contostavlos's lawyers took swift action to ensure the video, which allegedly shows her performing oral sex on a former lover, was deleted.
Representatives for Contostavlos said that they would not be commenting on "speculation about her personal life".
Take a look through some highlights from Tulisa's career in our gallery below:
> N-Dubz star Dappy wanted naked photo leak, says girlfriend