Spears and her ex-husband Kevin Federline are battling for custody of their two young sons.

TMZ said Federline's attorney, Vincent Kaplan' title='Mark Vincent Kaplan' class='tpstyle'>Mark Vincent Kaplan, served it with papers late Monday, requesting video footage it shot which apparently showed Spears out and about on the day she claimed she wasn't feeling well enough to attend a deposition appointment.

Media reports said she did not show up for the deposition because she was suffering from anxiety.

Federline has been given physical custody of the former couple's children, while Spears has been granted limited, supervised visits.

Kaplan said last week he planned to seek "some kind of remedy" against Spears for repeatedly failing to show for a Los Angeles deposition.