A divorce attorney in Manhattan who sued a former client for unpaid legal fees must return the $12,500 he has already collected, and he may not recover the remaining $21,660, a state judge said.

Manhattan Civil Court Judge Frank Nervo (See Profile) said Donald O’Sullivan filed his retainer agreement much later than required and sent billing statements to his client, Beverley Ward, so infrequently as to violate the court’s rules governing attorneys in domestic relations matters.