In a joint statement, Jamie and Lynne Spears said they were "extremely disappointed" to learn their troubled daughter had been released.

"As parents of an adult child in the throes of a mental health crisis, we were extremely disappointed to learn that over the recommendation of her treating psychiatrist, our daughter Britney was released from the hospital that could best care for her and keep her safe," the statement said.

"We are deeply concerned about our daughter’s safety and vulnerability and we believe her life is presently at risk. There are conservatorship orders in place created to protect our daughter that are being blatantly disregarded. We ask only that the court’s orders be enforced so that a tragedy may be averted."

The 26-year-old’s release came after a series of legal developments in which her father fought for control of the pop star and her estate, her frequent companion was ordered to stay away from her, and her mother vividly described her daughter’s fragile state and the strange behaviour that led to her being taken to hospital on January 31.

The singer has been in a spiral of increasingly bizarre behaviour since November 2006, when she filed for divorce from Mr Federline.

Britney ’drugged by Svengali manager’ - Feb 6 2008
A restraining order against the man who has been at Britney Spears’ side during her downward spiral portrayed him as a Svengali figure who held the singer a virtual hostage in her home, drugged her, took over her finances and controlled the ravenous paparazzi "like a general".

The order against 33-year-old Sam Lutfi was based on a lengthy declaration from Britney’s mother, Lynne, who says they met in October 2007, when he "essentially moved into Britney’s home and has purported to take control of her life, home and finances".

The documents released by the court on Tuesday ordered Mr Lutfi to stay away from Britneys.

On Monday, Mr Lutfi said: "I have no problems with anyone writing anything negative against me. My image is not of concern, hers is." He has not responded to further press inquiries.

Lynne Spears said in the order that Mr Lutfi "drugged Britney, he has cut Britney’s home phone lines and removed her cell phone chargers. He yells at her. He claims to control everything -- Britney’s business manager, her attorneys and the security guards at the gate".

Much of the declaration centres on the night of January 28, just a few days before Britney was taken to a hospital psychiatric ward. Her mother outlined increasingly bizarre behaviour through the night, and said her daughter asked at one point: "When do I get to see my babies?" to which Mr Lutfi answered: "Wednesday."

Manager drugged Britney, claims mum - Feb 6 2008
A restraining order aimed at Britney Spears’ friend and manager Sam Lutfi alleges that he drugged her, took over her life and finances and controlled the paparazzi who pursued her for months.

The order, based on a lengthy declaration from Britney’s mother, Lynne, says that the singer met Mr Lutfi in October 2007 and "Mr Lutfi has essentially moved into Britney’s home and has purported to take control of her life, home and finances."

The documents released by the LA court ordered him to stay away from her and stop the harassment.

In a section of the order that detailed previous harassment, Lynne Spears said "Mr Lutfi drugged Britney, he has cut Britney’s home phone lines and removed her mobile phone chargers. He yells at her. He claims to control everything."