ALBANY, N.Y. (AP) — A private investigator says a former upstate New York congressman hired his firm to tail a woman as part of child custody matter, and then refused to pay the investigator for his services.

Alliance Worldwide Investigative Group CEO Mario Pecoraro says he is suing John Sweeney for nearly $3,500 in investigative work his firm did for the former U.S. House of Representatives member from the Albany area. The Times Union of Albany reports Pecoraro said in court Wednesday that Sweeney did not pay his last two invoices.

Sweeney has been married three times and it was unclear if the investigator was hired to follow his current wife or a former wife.

Sweeney has filed a counter claim for $5,000, saying Alliance was professionally negligent.