Chart stars Jet had to play on without their singer last night after the frontman collapsed on stage and passed out twice during the show.

Collapse: Nic Cester had to be helped off stage

The band, promoting third album Shaka Rock, looked on as Nic Cester keeled over during the Australian band's second track at London's Hard Rock Cafe. He had to be helped from the stage by his manager.

The singer had felt unwell prior to the show and had been tested for swine flu although he was given the all-clear.

Jet - best known for their single Are You Gonna Be My Girl, which was famously used in an iPod ad campaign - soldiered on for a further three songs without Cester.

Bandmate Mark Wilson, the group's bass player, said they had not considered cancelling the show beforehand despite the singer's condition.

"You've got to do it, you can't just cancel stuff. It's disappointing for people who come to see you and, unless you can't sing, there's no real reason to cancel something, I think, you know," said Wilson.

Cester was given an injection to settle his stomach before the show, which was being staged by Q magazine as part of its monthly Q The Music Club series of gigs.

He was taken by ambulance to University College Hospital, where he was treated for symptoms of gastroenteritis, acute vomiting and dehydration and kept in overnight for monitoring.