An Army captain from Oregon charged with stealing nearly $700,000 from the government while in Iraq pleaded not guilty Thursday to charges including theft of government property and money laundering.

A federal grand jury indictment alleges that between April 2007 and February 24. 2009, Capt. Michael Dung Nguyen, 28, stationed at Fort Lewis, Wash., stole more than $690,000 entrusted to him as the battalion civil affairs officer in Muqdadiyah, Iraq.

Prosecutors say the funds were designated for local commanders in Iraq and Afghanistan for urgent humanitarian relief and reconstruction needs.

The indictment alleges Nguyen used some of the money to buy a new BMW M3 and a Hummer H3T, along with computers, electronics and furniture.

Court documents available Thursday did not list his Oregon home town but the indictment said he mailed bundles of stolen $100 bills home before he returned from Iraq and say he opened bank accounts in Oregon and elsewhere. The individual deposits were less than $10,000 but he sometimes made numerous deposits on the same or consecutive days, according to the indictment.

U.S. Attorney Karin Immergut said an investigation began after Internal Revenue Service agents spotted a suspicious pattern with the deposits.

She said the charges indicate a "flagrant and reprehensible disregard" for military honor.

U.S. Magistrate Judge Paul Papak set a May 5 trial for Nguyen, who will be tried as a civilian.

Nguyen was released to return to Fort Lewis near Tacoma, Wash.

"Fort Lewis has and will continue to cooperate with the investigation in this case as necessary," said Joseph Piek, Fort Lewis spokesman.

"The Army is a values-based organization, and for a commissioned officer to be indicted in a case such as this is a serious matter," Piek added.

Nguyen, a 2004 West Point graduate, is assigned to Headquarters and Headquarters Company, 2nd Battalion, 23rd Infantry Regiment, 4th Stryker Brigade Combat Team, 2nd Infantry Division.