WASHINGTON (AP) — The deputy commander of U.S. nuclear forces, Vice Adm. Tim Giardina, was notified Wednesday that he has been relieved of duty amid a military investigation of allegations that he used counterfeit chips at an Iowa casino, the Navy said.

The move is exceedingly rare and perhaps unprecedented in the history of U.S. Strategic Command, which is responsible for all American nuclear warfighting forces, including nuclear-armed submarines, bombers and land-based missiles.