Britney Spears left the deposition in her custody battle for her two young boys nearly two-and-a-half hours after arriving at the offices of Mark Vincent Kaplan, Federline's attorney, TMZ.com reported.
The tainted star was caught on tape getting into a white Mercedes.
In an interview with TMZ, Spears' attorneys Sorrell Trope and Tara Scott said she was "in good spirits." TMZ also reported the deposition is expected to last for at least two days.
Spears spoke to photographers in a British accent, as she has been doing lately.
Spears, wearing a dark blue top and jeans, arrived at the office in her white Mercedes-Benz SL65 with friend Sam Lutfi at 10:40 a.m. PT, People magazine reported.
Earlier this month, Spears appeared for the initial deposition hours late, resulting in the singer being deposed for just 14 minutes, Kaplan told reporters at the time. Another deposition would be scheduled, he said.
"The deposition proceeding did go forward today. It was scheduled for 9:45 to 11:45," Kaplan said. "However, it wasn't able to commence until 11:32. "You can imagine in 14 minutes there's not a lot of time to develop questions," he said.
Spears called in sick for a Dec. 12 court-ordered deposition, but was photographed that day driving with a friend. She also didn't show up for another scheduled session.
Spears, 26, and Federline, 29, have been wrangling over custody of their sons, 2-year-old Sean Preston and 1-year-old Jayden James.
Federline has temporary custody of the children because Spears has defied court orders. The two were married in October 2004 and divorced in July. Spears also does not have visitation rights at this time.
The Associated Press contributed to this report.