Actress Mischa Barton was reprimanded in a London nightclub toilet after trying to bundle a pal into a cubicle with her.

The former The O.C. star and a girlfriend were stopped from sharing a cubicle at Whisky Mist club in Mayfair during a recent night out by a toilet attendant.

A bystander tells Britain's Daily Mail newspaper, "Mischa looked like she was having a good night. After sitting with a few pals at her VIP table she dragged her friend Bridget into the loos.

"They tried to go into the toilet cubicle together but they were stopped by the toilet attendant. The lady said to her, 'What are you doing? You are not allowed to go in together, you have to come out now.'

"Mischa looked really p**sed off and embarrassed."

Barton then entered another cubicle alone - and spend several minutes inside in silence, prompting the attendant to ask if she was OK.

A loo user adds, "She took so long to emerge that everyone was worried about her. At one point the toilet attendant had to knock on her door twice to ask if she was alright. Then her mate was knocking to check she was feeling OK.

"When she came out of the cubicle, she was complaining about people knocking on the door."