Tulisa Contostavlos has caused controversy by flashing a gang sign on camera.

'The X Factor' judge has come under fire for making a C sign - linked to violent gang the Crime Scene Boys, also known as the Church Road Soldiers - with her hand whilst shooting a music video on a London estate on Sunday night (01.06.12).

An eyewitness told The Sun newspaper: ''She was strutting around throwing gang signs and hanging around outside the blocks of flats.

''She was swearing and trying to fit in with the other people who were around her from the estate.

''Making that C sign is what people do when they are a member of the Crime Scene Boys. It's a real mistake.''

The 23-year-old singer was filming a teaser for her new song featuring rapper Nines on the Church End estate in Harlesden, North-West London.

The Crime Scene Boys have been linked to drug dealing and gun violence, and Nines is known to make the sign in his own videos which reference the gang lifestyle.

Tulisa - who split from 'Skins' actor Jack O'Connell in June - has vehemently denied the gang link, claiming the letter C was supposed to represent her home district of Camden.

The 'Young' singer released a statement last night which read: ''I filmed a street video on Sunday night for a track on my album.

''The video was a collaboration with the rapper Nines. When we were filming on the street loads of other people turned up and joined in the shoot.

''When I was holding my hands in the C sign, this was as a tribute to Camden, my home town and where N-Dubz began.

''I am not aware that this sign has anything to with any street gang and I 100 per cent do not endorse any gang violence in any form.''

Tulisa also ruffled feathers last night (03.07.12) by causing a twitter spat with her cousin and N-Dubz bandmate Dappy.