There are new fears for troubled Britney Spears after she was reportedly seen downing shots of booze after a disastrous comeback gig.

The singer, who recently spent time in rehab, enjoyed a wild party in Miami into the early hours of the morning.

She hit Mansion in South Beach at about 2.15am before heading to SET for an all-night bash.

Here Britney necked "Purple Hooter shots - part vodka, Chambord and 7-Up", according to the Miami Herald, an American newspaper.

The Herald provided further details about Britney's antics at the club: "She asked the DJ to play Bob Sinclair's Hold On, Fergie's Glamorous and 'anything by Nelly Furtado".

"She was doing lots of shots and dancing around like a crazy lady, she's definitely back on the scene."

Earlier that night Britney performed a rather shambolic gig at Mansion.

And we're told the DJ belted out Justin Timberlake's new tune Summer Love the minute she walked off stage.

After her gig Brit headed to the Raleigh Hotel in a skimpy black bikini at about 1am for a dip in their pool.

Then she went back to Mansion, wearing a red bandana dress and fedora to cover her blonde hair extensions.

SET was her final destination, where she stayed in the VIP room, which has a huge glass window overlooking the crowd, until 5am.