Published Tuesday, 03 September 2013
The N-Dubz singer hosted a bash for pals at her home on Sunday and uploaded photos of the fun on her Instagram page.
One image showed Tulisa and her friends sitting on a couch with what appears to be 'laughing gas' cylinders on a coffee table - but she quickly took down the snap and replaced it with a cropped version.
The substance is legal in the UK but anti-drugs campaigners have criticised stars who have been photographed apparently inhaling the gas from balloons.
Contostavlos is no stranger to controversy - she was arrested in June after she was allegedly caught on camera setting up a cocaine deal worth £800 for an undercover reporter from The Sun newspaper.
She remains on police bail alongside her rapper pal Mike GLC, who stands accused of selling the illegal substance.