An acting inspector general who was himself under investigation for allegations he misused his office and softened reports to keep from embarrassing the Obama administration stepped down from his job late Monday.

Charles K. Edwards, who was charged with overseeing the vast Department of Homeland Security and its many bureaus and agencies since the retirement of the former inspector general, had faced a broadening Senate probe this year that focused on whether he had altered and delayed investigations to please the agency and the White House. News of his departure to another office within the department he oversaw came just three days before he was scheduled to testify at a Senate hearing on questions about his lack of independence.

Edwards, who declined to comment Monday night, has denied the claims and insisted he did nothing wrong. In a statement he issued in July, Edwards said: “I am very disturbed that false allegations have been made against me, but more importantly, I am very concerned that this matter may negatively impact the important oversight work of the Office of Inspector General...I will defend myself against these personal attacks.”

A group of whistleblowers within his office had claimed Edwards was eager to win the White House nomination to be the permanent inspector general after two years in the acting role, and was easily susceptible to political pressure from the top leadership of the Department of Homeland Security.

Whistleblowers asserted Edwards and his top staff pushed to change findings in reports and delay investigations. Others accused him of retaliating or threatening to retaliate against staff who resisted him. Other claims included that he used staff to do personal work for him.

One of the most controversial chapters of Edwards’ time as acting inspector general came after Congress requested that his office investigate a major scandal within the Secret Service: more than a dozen agents had gone out for a night of heavy drinking and hired prostitutes in Cartagena, Colombia, during a presidential trip there in April 2012. His office was also charged with looking more deeply into the Secret Service’s culture. Investigators in his office complained to their colleagues that Edwards’ top staff insisted on removing references to evidence that contradicted public statements by then-Secret Service Director Mark Sullivan and White House spokespeople.

In July, Sens. Claire McCaskill (D-Mo.) and Ron Johnson (R-Wis.), the chairman and ranking member of the Financial and Contracting Oversight subcommittee who had been investigating Edwards, complained in a letter to him that he was not cooperating with the panel’s probe. Johnson also aired concerns that the inspector general’s public reports on the Secret Service were drastically different from the more detailed, non-public reports, and of the delay in the culture report.

Edwards vowed to complete “an independent and transparent” look into the Secret Service’s culture 18 months ago. His office says it now plans to release that report likely in the next two weeks.

Late last month, the White House announced the president had nominated John Roth, a top criminal investigator at the Food and Drug Administration, to become the permanent inspector general. Thursday’s Senate hearing will likely be canceled.