by Barbara Starr

(CNN) -- The Pentagon's Office of Inspector General has opened an investigation into allegations related to Rear Admiral Ronny Jackson, President Donald Trump's one-time personal White House physician whose nomination as veterans affairs secretary was withdrawn amid allegations of misconduct and poor administration of the White House medical office.

"The DoD Office of Inspector General has initiated an investigation into allegations related to Rear Admiral (Lower Half) Ronny L. Jackson," IG spokesman Bruce Anderson said in a statement to CNN.

Anderson would not say if the investigation is administrative or criminal in nature, although the IG can conduct both. The investigation was initiated in the last month, he said, and includes interviews with persons he declined to identify.

Jackson is facing allegations of personal and professional misconduct by unidentified current and former colleagues including that he casually dispensed prescription drugs.

Confrontations, possible privacy violations

In addition, Vice President Mike Pence's physician privately raised alarms within the White House last fall that Jackson may have violated federal privacy protections for a key patient -- Pence's wife, Karen -- and intimidated the vice president's doctor during angry confrontations over the episode.

In April, shortly after Jackson's nomination was withdrawn, the Pentagon issued a statement, saying the IG had "received the allegations and is assessing what investigations and reviews have already been conducted related to these issues, any jurisdictional issues that may relate to the allegations, and the scope of the allegations and complaints related to these issues."

"The Inspector General's office will determine what investigations or actions are warranted regarding these allegations and complaints," the statement said at the time.

Jackson has been nominated for a second star. Now that his nomination has been withdrawn, he would have to be confirmed for the second star by the Senate or put in for retirement. If he retires, it would have to be determined by the Navy when he last served honorably and he would retire at that level.

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