In another shake-up, State Dept.'s acting inspector general resigns amid Pompeo probes

The move comes after he served fewer than three months on the job.

After fewer than three months on the job, the State Department's acting inspector general has resigned in another major shake-up of the watchdog office, ABC News has confirmed.

Stephen Akard, a longtime aide to Vice President Mike Pence, became acting IG in May after Steve Linick, a career civil servant, was fired.

Akard "has announced he is returning to the private sector after years of public service. We appreciate his dedication to the Department and to our country," a State Department spokesperson told ABC News Wednesday.

A Trump appointee, Akard had been serving as director of the Office of Foreign Missions. After becoming acting IG, Akard said he would "not exercise the authorities or duties" of director and would recuse himself from any investigation involving the Office of Foreign Missions, "matters I worked on, in a substantive way," and individuals he knows personally.

That was not enough to quell Democratic lawmakers' concerns about a conflict of interest.

Inspectors general are independent federal watchdogs assigned to different agencies and tasked with investigating corruption, malfeasance and waste. The State Department Office of Inspector General was investigating Pompeo and other senior officials for the department's use of an emergency authority to bypass Congress and sell $8 billion of arms to Saudi Arabia and the United Arab Emirates, as well as Pompeo and his wife's use of staff to run personal errands.

House Democrats have been probing Linick's firing -- issuing new subpoenas on Monday for four State Department officials to testify about the decisions to fire Linick and to approve the emergency arms sales.

Akard was not among the recipients, although his resignation may make him available to speak to the committee now as the department has rejected previous subpoenas for current officials.

Akard had told his staff he had been approached about becoming acting IG in April, weeks before Linick was formally notified of his firing, ABC News reported in June.

Pompeo has denied that Linick's firing was retaliation for probes -- at first saying he was unaware of any investigations and then saying while he answered questions about the arms sale probe, he didn't know the full scope.

In closed-door testimony in June, Linick confirmed that he was conducting an "administrative review" of allegations that Pompeo and his wife Susan Pompeo improperly used department staff for personal errands as well as of the emergency arms sales, and he disclosed three previously unknown investigations involving Pompeo's office: an audit of the special immigrant visa program, a review of the International Women of Courage Award and a third involving individuals in the Office of the Protocol amid allegations of "workplace violence" there.

"We were not judging whether the policy was good or bad. We are nonpartisan. We just look at how policies are carried out and whether they comport with applicable regulations and law," he said, adding that a senior aide to Pompeo told him the investigation wasn't "appropriate" and tried to "bully" him to stop it, according to a transcript published by the House Foreign Affairs Committee.

ABC News's Benjamin Siegel contributed to this report.