Ananova:

Britney Spears' whirlwind marriage looks destined to end as suddenly as it began, amid claims that her 'joke' wedding vows are being annulled.

The star reportedly wed childhood friend Jason Alexander in Las Vegas in the early hours of Saturday after a night of partying.

Wearing jeans and a baseball cap Spears, 22, was said to have been walked down the aisle by a hotel barman. But the exchange of vows was a joke that went "too far" according to sources close to the singer.

Both Spears and her 22-year-old husband apparently signed an annulment in the presence of lawyers shortly after the ceremony. It will reportedly come into effect when the courts open.

The online version of People Magazine said there were no family or friends present at the ceremony. It said the pair planned their rushed wedding on Friday night as they partied at the Ghostbar, part of the Palms Casino Hotel in Las Vegas. They were reportedly driven to the Little White Wedding Chapel.

According to People, when they were told they needed a licence they were driven to the Clark County Marriage Bureau office at the downtown Las Vegas courthouse. Documents filed early on Saturday with the Clark County marriage bureau showed they were granted a marriage licence, according to the Las Vegas Review Journal.

George Maloof, owner and operator of the Palms Casino Hotel, confirmed that the wedding had gone ahead at about 5.30am on Saturday. "Nobody knew it was coming," he said. But he denied reports that Spears had been partying too hard over the New Year period.

Referring to stories that she had been carried out of the Rain nightclub inside the Palms on New Year's Eve, he said: "I was with her the whole night. None of those reports were accurate. She was just having a good time."

Meanwhile, Alexander was back in his home town, according to his grandfather, Robert Alexander. He told Entertainment Tonight: "He'd been through a lot. We picked him up in New Orleans coming back and he didn't have much to say." He added: "I wish them well. Whatever happens, happens."

He said Spears and Alexander had also spent Christmas Eve together. According to the People Magazine website, the ceremony was videotaped and Spears has been showing the footage off to friends. Spears' publicist has yet to comment on the reports.