The Environmental Protection Agency’s inspector general is opening an investigation into allegations that the agency’s former air quality chief violated ethics rules. Bill Wehrum resigned from his position as head of the air-quality office last month amid accusations that he helped members of the energy industry who were once his clients when he was a lawyer and lobbyist for oil, gas, and coal companies. The IG will reportedly investigate whether Wehrum’s work at the EPA to rollback climate change and air pollution regulation purposefully benefited his former clients. Under ethics rules, public officials are not permitted to take part in “particular matters” involving parties they worked with or for in the private sector. The Trump administration’s EPA has been the subject of several ethics investigations, including more than a dozen inquiries into the agency’s former administrator Scott Pruitt.