But the pop star's former husband Kevin Federline arrived with his lawyer for the hearing, which is being held behind closed doors before Superior Court Commissioner Scott Gordon.

Monday's hearing was ordered after the judge suspended Spears' right to visit her sons, one-year-old Jayden James and two-year-old Sean Preston, following a stand-off at her home earlier this month.

Mark Vincent Kaplan, Mr Federline's lawyer, said police and emergency medical technicians who were summoned to Spears' home on January 3 after she refused to return the boys to her ex-husband were expected to testify.

During the incident, Spears locked herself in a room with one of the boys and was later taken to a hospital in an ambulance chased by photographers.

Spears was placed on an involuntary hold on grounds she was a danger to herself or others and left Cedars-Sinai Medical Centre a day and half later.

Mr Kaplan said he knew it was only a temporary measure when he obtained emergency court orders two weeks ago granting sole physical and legal custody to Federline.

Spears has also missed previous court hearings, including a court-ordered deposition on December 12 when she called in sick. She also arrived nearly two hours late at a lawyer's office on its rescheduled date, January 3.