Sienna Miller has enjoyed a wild night partying in London.

The 'Edge of Love' star has sparked rumours she has split from actor Balthazar Getty after spending the evening with Leonardo DiCaprio, Josh Hartnett and Olivier Martinez on Friday (07.11.08).

A source said: "It was a really heavy night for Sienna. She didn't stop partying until around 4am."

Sienna, who looked stunning in a revealing white mini-dress and black high heels, began her night with Oliver - who has previously dated singer Kylie Minogue - at London's private dining club Mosimann's.

The exclusive club was hosting the launch of a new Hollywood-themed dominoes game and Sienna and Olivier laughed and joked together as they took over a gaming table.

Sienna and Olivier then went to American restaurant Automat for dinner, and were joined by 'Pearl Harbor' actor Josh until 2am.

The 26-year-old blonde beauty continued partying at new nightspot Jalouse with Josh and Leonardo until the early hours.

It has been claimed Sienna's relationship with Balthazar has cooled because she is upset the 'Brothers and Sisters' actor is stalling on his plans to divorce his wife Rosetta.