Federline and his lawyer were on hand as Superior Court Commissioner Scott Gordon began the hearing, which was scheduled after Mr Gordon earlier this month suspended Spears’ right to visit her two sons.
Mr Gordon allowed reporters into the courtroom for about one minute before he announced that the hearing was being closed.
The commissioner granted a motion yesterday from Spears’ attorneys to quash a subpoena, but there was no information about what the subpoena involved or to whom it had been issued.
A group of people, possibly witnesses, were later allowed into the courtroom.
Superior Court spokesman Allan Parachini, who was in court, told reporters the first of an expected eight or nine witnesses had taken the stand.
A throng of photographers and reporters waited outside the downtown courthouse to see if Spears, 26, would come to what one attorney described as “the most significant hearing in the case so far”.
Law enforcement officers watched over the scene.
But Spears has had trouble making recent legal dates: On December 12, she called in sick for a court-ordered deposition, then arrived nearly two hours late at an attorney’s office on its rescheduled date, January 3.
Neither Spears nor Federline were under order to appear yesterday. But Federline’s attorney, Mark Vincent Kaplan, suggested in an interview with The Associated Press on Sunday that it would be important for her to be there.
“You can’t phone this one in,” he said.
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.
Among those expected to testify, Mr Kaplan said, were police and emergency medical technicians who were summoned to Spears’ home on the night of January 3.
A court-appointed monitor called police when Spears refused to hand over Jayden James, one, 1, and Sean Preston, 2, to Federline’s security guard.
She locked herself in a room with one of the boys.
Police officers spent hours at the house and then called fire department paramedics, who took Spears to a hospital.