The federal government’s top ethics officer prodded the Environmental Protection Agency to scrutinize Administrator Scott Pruitt’s unorthodox rental of a Capitol Hill condo and travel habits, saying the American public needs to have confidence all allegations are fully investigated.

David Apol, the acting director of the Office of Government Ethics, urged the EPA’s top ethics officer to dig into the issues amid mounting scrutiny of Pruitt’s rental, his frequent reliance on first-class airfare and the agency’s decision to boost the salary of two top aides.

“Public trust demands that all employees act in the public’s interest, and free from any actual or perceived conflicts,” Apol said in the letter dated April 6.

“The success of our government depends on maintaining the trust of the people we serve,” Apol wrote Kevin Minoli, the EPA’s principal deputy general counsel and its designated ethics official. “The American public needs to have confidence that ethics violations, as well as the appearance of ethics violations, are investigated and appropriately addressed.”

The letter comes amid a flurry of questions about some of Pruitt’s practices as EPA administrator. Pruitt has come under fire for raises worth tens of thousands of dollars for two close aides over the objections of the White House and taking first-class flights, as well as reports that several EPA staff members who questioned his practices were transferred to other jobs. EPA officials have defended Pruitt’s first-class airfare as necessary to ensure the administrator’s security.

President Donald Trump has defended Pruitt’s spending on personal security and his $50-a-night room lease from an energy lobbyist’s wife, which have prompted calls for Pruitt’s resignation and a House investigation.

“While security spending was somewhat more than his predecessor, Scott Pruitt has received death threats because of his bold actions at EPA,” Trump said in a Twitter message late Saturday. “Rent was about market rate, travel expenses OK. Scott is doing a great job!”

Under unusual rental terms, Pruitt was able to pay $50 per day to lease a bedroom in a condo steps from the U.S. Capitol — but only on the nights he stayed there.