One of the top executives of a consulting firm that the Environmental Protection Agency has recently hired to help it with media affairs has spent the past year investigating agency employees who have been critical of the Trump administration, federal records show.

The firm, Definers Public Affairs, based in Virginia, specializes in conducting opposition research, meaning that it seeks to find damaging information on political or corporate rivals.

A vice president for the firm, Allan Blutstein, federal records show, has submitted at least 40 Freedom of Information Act requests to the E.P.A. since President Trump was sworn in. Many of those requests target employees known to be questioning management at the E.P.A. since Scott Pruitt, the agency’s administrator, was confirmed.

Mr. Blutstein, in an interview, said he was taking aim at “resistance” figures in the federal government, adding that he hoped to discover whether they had done anything that might embarrass them or hurt their cause.