An Army doctor is under investigation after questioning on YouTube whether President Barack Obama is U.S.-born—then disobeying orders to report for duty in Afghanistan.

Lt. Col. Terrence Lakin failed to report to Fort Campbell, Ky., on Monday, showing up instead at his old job in a clinic in the Pentagon, Lt. Col. Christopher Garver, an Army spokesman, said yesterday. Lakin was reassigned immediately to Walter Reed Army Medical Center in Washington while the investigation is under way.

Though officials in Hawaii verify that Obama was born in the state, so-called birthers claim he was born outside the United States and is ineligible to be president. Lakin says he wants to see the birth certificate as proof Obama is his commander in chief and thus that the deployment order for Afghanistan is legal.

Lakin is under investigation for his failure to report for deployment and for conduct unbecoming an officer.

A Greeley, Colo., native, Lakin said in a video posted on YouTube that he was an 18-year Army veteran “;choosing to disobey”; orders he says are illegal, including an order to deploy to Afghanistan for a second tour. He said he was doing so at “;great peril”; to his career, “;inviting my own court-martial.”;

A court-martial is only one of the punishment options, and among the handful of other known birthers in the military, some have merely received administrative reprimands.