FILE PHOTO - Ronny Jackson, U.S. President Donald Trump's nominee to be U.S. Secretary of Veterans Affairs, meets with Senator Jon Tester (D-MT) at his office on Capitol Hill in Washington, U.S., April 17, 2018. REUTERS/Joshua Roberts/File Picture

WASHINGTON (Reuters) - The U.S. Defense Department’s inspector general has opened an investigation into misconduct allegations against White House physician Ronny Jackson, the inspector general’s office said in a statement on Monday.

President Donald Trump nominated Jackson to be veterans affairs secretary in March, but Jackson withdrew from consideration a month later amid allegations he had overseen a hostile work environment as White House physician, drank on the job and allowed the overprescribing of drugs.

Jackson, a U.S. Navy rear admiral, has denied the allegations.

“The DoD Office of Inspector General has initiated an investigation into allegations related to Rear Admiral (Lower Half) Ronny L. Jackson,” Bruce Anderson, spokesman for the inspector general’s office, said in a statement.

Democrats on the Senate Veterans’ Affairs Committee have said more than 20 current and former colleagues had come forward to accuse Jackson of prescribing himself medications, getting drunk at a Secret Service party and wrecking a government vehicle.

Jackson has worked as a presidential physician since 2006. After withdrawing his nomination for the VA post, Jackson stopped serving as Trump’s lead physician.