Billy Zane spent a wild evening attempting to pick up women behind Kelly Brook's back, Mail Online can reveal.

The actor, 42, worked his charms at a Los Angeles nightclub, where witnesses described his behaviour as 'flirtatious beyond belief'.

On the rocks? Kelly Brook and Billy Zane recently rekindled their romance after splitting up earlier this year. Friends say Kelly will be furious when she finds out about her boyfriend's night on the town

A source said: 'Billy was hitting on every woman in sight.

'He bought round after round and was making it plain that he was up for meeting someone.

'He was a single guy on a mission. Each time a pretty girl walked in, he couldn't take his eyes off them and would offer drinks to anyone he struck up a conversation with.'

Scene of the crime: The Bar, on LA's Sunset Boulevard, where Billy was spotted trying to pick up women

The incident took place on Monday  at hip hotspot The Bar on LA's Sunset Boulevard.

Titanic star Zane came in with a male friend, looking dapper in a cashmere blue V-neck sweater and tweed flat cap.

Kelly Brook is currently filming in Virginia, 3,000 miles away from Billy

The source told the Mail  Online: 'Billy was pretty much the only celebrity there, so he had the attention of most of the pretty girls.

'He was really in his element.

'He was showering the girls with compliments, saying things like "You're so hot, let me buy you a drink.'

'He was cuddling up to a blonde girl in the corner of the bar at one point.'

The Bar, which is in the heart of West Hollywood, is a known haunt for singletons, especially on Monday nights - the evening Billy worked his charms.

The news is likely to raise serious questions about the state of his relationship with Strictly Come Dancing star Kelly.

They called off their engagement earlier this year but have since got back together.

Kelly is currently on the judging panel of reality television show Dirty Dancing: The Time Of Your Life which is being filmed in Virginia.

A source close to the couple said: 'She's going to hit the roof when she finds out about this.'