Britney Spears - Contributed

los angeles (reuters)

Troubled pop star Britney Spears was reported on Wednesday to have left a Malibu rehabilitation centre less than 24 hours after checking in.

Celebrity websites TMZ.comand ETonline.com, citing unidentified sources, said the 25-year-old singer left the residential centre early on Wednesday morning.

Spears' manager Larry Rudolph confirmed on Tuesday that the singer had voluntarily checked in to a facility and asked for privacy. Rudolph could not immediately be contacted on Wednesday.

Spears made world headlines on the weekend after shaving her own head at a Los Angeles area salon following weeks of partying at clubs in Hollywood, Las Vegas and New York since filing for divorce from husband Kevin Federline in November.

The hair-shaving incident raised concern about her mental state and followed reports that the former child star had entered rehab on the Caribbean island of Antigua last week, only to drop out 24 hours later.