A tearful Britney Spears defiantly shaved her head at a Los Angeles hair salon after the owner refused to take part in the embattled pop star's latest extreme makeover.

The Friday evening visit to Esther's Haircutting Studio in the Tarzana district of Los Angeles was followed by a trip to a tattoo parlour where the 25-year-old mother of two young sons added two designs to her body.

The transformation came on the same day People magazine and other entertainment media reported that Ms Spears recently entered a rehabilitation centre in the Caribbean island of Antigua and checked out a day later. The reports were denied by Ms Spears's representatives.

Ms Spears's busy Friday night began in the salon of Esther Tognozzi, who told the syndicated television gossip show Extra that she was afraid to shave Ms Spears's head in case she was sued for ruining the singer's image.

After Ms Tognozzi protested that Ms Spears was maybe being "hormonal" and would feel differently the next day, Ms Spears coolly "grabbed the buzzer and started buzzing her own hair off... I just cleaned it up when she was done with it," she said.

Ms Tognozzi said Ms Spears seemed to be "just there in body and not really emotionally there," but did get "a little bit teary-eyed" when she realised her mother might get upset.

The whereabouts of the hair was a mystery, although an enterprising person in Pennsylvania was selling 10 lots of the purported locks on eBay at $50 per lot.

After Ms Spears's bodyguard paid Ms Tognozzi a tip, the party headed to the Body and Soul parlour in the suburb of Sherman Oaks, where she spent $80 for a black-white-and-pink cross on her lower hip and red-and-pink lips on her wrist.

An artist at the parlour, Emily Wynne Hughes, said Ms Spears appeared "distraught and disturbed," and was difficult to work with.

"She was screaming and flipping out from the pain and wiggling her body all around," Ms Hughes told reporters.

Ms Spears's representatives could not immediately be reached for comment.

Britney Spears rose to fame eight years ago in the guise of a virginal schoolgirl and had hits with tunes such as Oops!... I Did it Again and the Grammy-winning Toxic. As little girls around the world clamoured to mimic their idol, Ms Spears ditched the clean-cut image by kissing Madonna at an awards show, using public restrooms in bare feet and marrying a childhood friend for two days.

She has become a fixture on the nightclub circuit since her split in November from her second husband, Kevin Federline, a former back-up dancer.

Ms Spears was repeatedly photographed in December climbing out of automobiles without wearing underpants while in the company of celebrity Paris Hilton.

Ms Spears and Ms Hilton recently made the cover of Newsweek magazine with a story headlined The Girls Gone Wild Effect and a poll of readers who said celebrities like them were having too much influence on young girls.

In January, Ms Spears posted a message on her website acknowledging the negative publicity, while writing, "I look forward to coming back this year bigger and better than ever and to reaching out to my fans on a more personal level."

Her website, www.britneyspears.com, was down on Saturday, evidently also undergoing a makeover.