Britney Spears has asked a Los Angeles court for a restraining order against a Japanese man she claimed has been stalking her for the last three months.

The singer filed a petition at the city's Superior Court against Masahiko Shizawa of Yokohama, claiming the 41-year-old had "tracked and attempted to contact" her at her house in Los Angeles since September.

She also claims Mr Shizawa has called at another of her homes and also a home used by her parents, both outside California.

It is claimed Mr Shizawa sent notes to the pop star saying "I'm chasing you", and refused to leave her property when asked to.

Spears' lawyer, Joel Strote, asked that Mr Shizawa be banned from coming within 300 metres of the singer, and from contacting her at all.

The singer has had a bad year, with her parents separating

However, it was unclear whether or not the request had actually been granted.

Spears' spokeswoman, Lisa Kasteler, said she could not comment "for security reasons", although she added she had not discussed the situation with the singer.

While judges are often willing to grant temporary restraining orders for celebrities, a full hearing would be needed to make the injunction a permanent one.

The 21-year-old performer is currently taking a six-month sabbatical from music.

She has had a troubled year, with her relationship with N'Sync star Justin Timberlake ending, and her parents separating.

Her debut movie performance in Crossroads was slated by film critics, and a restaurant she opened in New York suffered a setback after two diners claimed they suffered food poisoning there.

She has since distanced herself from the venue, called Nyla.

Spears has recently been in Italy staying with fashion mogul Donatella Versace.

Earlier this year her spokespeople denied claims she was planning to take a two-year break from music.