Britney Spears has completed the treatment at the third attempt

She entered the Promises Malibu Alcohol and Drug Rehab Treatment Facility on 22 February having sparked concern among fans after publicly shaving her head.

The singer, 25, left the clinic "after successfully completing" the programme, her manager Larry Rudolph said.

"We ask that the media respects her privacy as well as those of her family and friends at this time," he added.

The star completed the treatment at the third attempt after twice reportedly entering the clinic but then leaving again after just one day.

The Promises clinic in Malibu promises "uncommon luxury"

The clinic's website says it is one of the world's leading centres for "inpatient treatment to alcoholics and addicts hooked on prescription or illegal drugs".

"During the critical stage of early recovery, we work to ensure that new participants experience the safest and most comfortable drug detox and alcohol detox possible," it says.

"Using the most effective techniques available in drug and alcohol treatment, an individualised treatment plan is developed for each client by our clinical team to assure a successful recovery."

The clinic offers patients "uncommon luxury" and is "tucked into the Santa Monica Mountains with a gorgeous panoramic view of the Pacific Ocean", it adds.

A family court hearing involving Spears' husband Kevin Federline was postponed when the singer went back in for the third time.

Spears has two children with Federline - five-month-old Jayden James and Sean Preston, aged 17 months.