Washington, Jun 5 (IANS): The Pentagons investigative watchdog has launched a probe into improper conduct allegations against Ronny Jackson, the White House military physician who withdrew from consideration as the President nominee to lead the Department of Veterans Affairs.

The Defence Department Office of Inspector General, which investigates possible wrongdoing by the Pentagon and its staff, confirmed in a statement on Monday that it recently initiated a probe into Jackson, reports The Washington Post.

A spokesman declined to go into the details of the probe.

Soon after Trump nominated Jackson to the Cabinet post, the ranking Democrat on the Senate Veterans' Affairs Committee, Senator Jon Tester of Montana, released a two-page summary of allegations that had surfaced against the White House physician.

It included accusations that he improperly prescribed drugs, created a hostile work environment and drank while on duty.

The White House said it conducted a thorough review of Jackson's record and found three minor incidents but no evidence that the physician was responsible for some of the more extreme allegations in Tester's document, including one accusing him of wrecking a government vehicle after drinking.

Jackson, who served as White House physician under three administrations, has denied any wrongdoing.

Trump came to the doctor's defence, accusing Tester of a smear campaign that devastated Jackson's family, The Washington Post reported.

He called on the Montana Democrat to resign.

Last month, White House press secretary Sarah Huckabee Sanders said Jackson was no longer serving as the President's personal physician but remained on the White House medical staff.

The Navy confirmed on Monday that Jackson remained detailed to the staff.