Katy Perrys Controversial Stage Moments Unveiled

 is seen groping 's butt and kissing a teenage fan on stage in disturbing clips that have resurfaced in the wake of sexual assault claim against the Teenage Dream singer, which she has denied.

In the viral footage Perry, then 27, put her hand on Bieber, who was 18 at the time, before mouthing 'Sorry Selena' into the camera.

The remark was an apparent reference to Bieber's on-off girlfriend at the time, , who would've been 19 years old. 

During her set, Perry also kissed a schoolboy fan on the lips on stage even though he grimaced and backed away as she did so, the film shows.

The footage resurfaced after Australian actress alleged that Perry sexually assaulted her at a nightclub in in 2010.

The claim by Rose, 40, against Perry, now 41, are now the subject of an investigation by police in Victoria, Australia.

Perry has strongly denied the allegations and said they were 'not only categorically false, they are dangerous, reckless lies'.

'Ms Rose has a well-documented history of making serious public allegations on social media against various individuals, claims that have repeatedly been denied by those named,' a spokesperson for Perry said.

The resurfaced convert footage appears to have been shot at the Capital FM Summertime Ball in Wembley Stadium in London in June 2012.

Perry and Bieber both played the event: he wore the same Union Flag top that appears in the clip and Perry is wearing the same black and white polka dot dress she wore on stage.

The footage shows the pair meeting backstage and Perry smiles and jumps up in the air.

A fresh-faced Bieber leans in for a hug and Perry puts her left hand on his back and does a big smile, the footage shows.

Seconds later her expression changes and she drops the hand to Bieber's left butt cheek.

Looking into the camera, she mouths: 'Sorry, Selena.' 

Bieber appears to be smiling and says something inaudible to Perry who tells him: 'Shut up!'

The footage from Perry's set shows her on stage with a teenage boy who introduces himself as Robert.

'Are you nervous?' Perry asks him and Robert nods. 'Staying in school?' asks Perry, and Robert nods again.

She tells him: 'That's good, you're going to be really, really popular on Monday.' 

Perry asks the boy: 'This is going to be awkward in front of your father (in the audience). Have you ever been kissed?'

Robert shakes his head no and Perry leans in to kiss Robert on the lips as the crowd cheers approvingly.

The footage shows him awkwardly moving his face away and avoiding her lips.

Undeterred, Perry keeps the boy on stage and tells him: 'Honey, you might be too young to understand this, but when a woman kisses you, you gotta kiss her back'.

Robert walks up to Perry and gives her a peck on the cheek, while she jokingly pretends to bite him.

Perry then announced that her husband, an apparent reference to British comedian Russell Brand, was there to 'surprise me' and Robert walked off the stage.