Pop star Britney Spears is under investigation for misdemeanor battery after a home staff member alleged the singer struck her, authorities said on Thursday.

The singer's lawyer Mathew Rosengart denied the allegation, calling it "overblown sensational tabloid fodder".

In California, where Spears lives, misdemeanour battery is a criminal offence that involves any intentional and unlawful physical contact with someone else.

The singer is alleged to have slapped her employee's mobile phone out of their hands during the encounter.

Spears’s lawyer said it was "nothing more than a manufactured 'he said, she said' regarding a cell phone, with no striking and obviously no injury whatsoever.

"Anyone can make an accusation, but this should have been closed immediately," he said.

"To its credit, the Sheriff's Office itself has acknowledged that the incident was classified as a 'very minor misdemeanour…' and confirmed 'there were no injuries'."

Spears has a home in Thousand Oaks, about 64 kilometers west of downtown Los Angeles.

Last month, Spears hired Rosengart as her lawyer in her continued fight trying to remove her father as her legal guardian in a conservatorship that’s been ongoing since 2008.

“This conservatorship is doing me way more harm than good,” Spears, 39, said in June. “I deserve to have a life.”

However, last week, it was reported that Jamie Spears filed legal documents saying that although there are no grounds for his removal, he will step down.

The documents say he is “the unremitting target of unjustified attacks” but “he does not believe that a public battle with his daughter over his continuing service as her conservator would be in her best interests".

The filing also says Jamie will fight the petition to force him out, but will work with the court and Rosengart, to “prepare for an orderly transition to a new conservator".

“We are pleased that Mr Spears and his lawyer have today conceded in a filing that he must be removed,” Rosengart said.

“It is vindication for Britney.”