MADISON, Wis. (AP) -- U.S. Air Force officials are investigating the Wisconsin National Guard's top commander.

It's unknown what prompted the Air Force Inspector General's inquiry into Brig Gen. Donald Dunbar or what it entails. The Wisconsin National Guard's spokeswoman says she isn't aware of any of the details. A message left with the Air Force press office wasn't immediately returned.

A spokesman for the National Guard Bureau says the inquiry is an "active, ongoing investigation of some kind," but his office was not aware of the circumstances or any other details.

Gov. Jim Doyle appointed Dunbar brigadier general in September 2007. The U.S. Senate still has not confirmed his promotion, however.

Dunbar says in a statement his priority remains protecting Wisconsin but didn't mention the investigation.

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