Katy Perry had to be helped out of Justin Bieber’s party in London on Sunday morning (10.06.12).

The pair had played the Capital FM Summertime Ball in Wembley on Saturday night (09.06.12) and after some overenthusiastic partying by the ‘Firework’ hitmaker at the teen heatthrob’s bash at Cirque Du Soir, she had to rely on bodyguards, her PA and some of her famous friends to help her out.

A source told the Daily Mirror newspaper: “Katy was in high spirits and very excited that Justin was there, as she loves Justin. And she’s good friends with Jessie J, so they had a catch up.

“Before long Katy had sunk a fair few vodka cocktails. She had big bottles of Ciroc and Belvedere vodka on her table. By 5am she seemed to be having some difficulty walking and suddenly fell to the floor. She was down for a while and it took a couple of her mates to get her up. Everyone was staring and there was quite a commotion. Even Max George from The Wanted stepped in to lend a hand.”

Katy, who attended the party with her boyfriend Rob Ackroyd, also gave clubbers a cheeky glimpse of her bum as she bent over while getting in to her car.