A former Army captain accused of stealing $400,000 in cash from the U.S. government while stationed at Kandahar Air Base in Afghanistan has pleaded guilty to theft and money laundering.

David Gilliam, 39, also pleaded guilty Tuesday to filing a false tax return for failing to list the stolen money as income. He faces up to 23 years in prison when he is sentenced in January.

Gilliam was accused of stealing the money between April 2004 and April 2005 while he worked as a disbursing officer for the Army's Alpha Detachment, 125th Finance Battalion at Schofield Barracks.

Gilliam admitted he took money from Kandahar and transported it to the U.S., authorities said.

In Afghanistan, Gilliam was responsible for disbursing funds to pay for projects, and documenting losses that occurred because of currency exchange rate fluctuations. He hid his theft by stating losses equal to the amount he stole, prosecutors said.

Last year, Gilliam told the Internal Revenue Service the money came from a dating service he had operated while stationed in Fort Clay, Panama, according to an indictment returned in February.