A judge has ordered an investigation into Britney Spears' conservatorship case.

The 'Gimme More' hitmaker appeared in court last week to claim that her father Jamie Spears - who has had control of her affairs for the past 11 years - committed her to a mental health facility against her will in her bid to be freed of her conservatorship.

And now, the judge presiding over the case has ordered a thorough investigation of all the people who take part in Britney's conservatorship, in order to properly assess whether the restraints on the singer should be loosened or modified.

In documents obtained by The Blast, Britney's judge ordered a probate court investigator to take a hard look at the singer's case, and said a full court investigator's report was to be filed before Britney's next hearing in September.

The job of a probate court investigator is to conduct extensive interviews with all the people involved in a conservatorship case, including guardians, conservators, doctors and even law enforcement officials who have had contact with the subject of the conservatorship.

According to The Blast, the investigator will also be reviewing medical and financial records, including custody agreements and contractual obligations.

The news comes after Britney claimed her recent stay in an unnamed Los Angeles mental health facility was arranged by her father, whom she also claims forced her to take drugs.

However, under the rules of the conservatorship Jamie does not have the power to either commit Britney against her will or to make her take prescription medication.

The singer's fans have started a social media campaign under the ''#FreeBritney'' hashtag to call for the conservatorship to end.

Outside the Los Angeles courtroom a number of protesters gathered with posters emblazoned with the words ''#FreeBritney''.

At a recent concert, Miley Cyrus shouted ''Free Britney'' during a rendition of her Hannah Montana hit 'Party in the U.S.A.', the lyrics of which reference the 'Toxic' hitmaker.