Justice Department prosecutors say three specialists and a former sergeant in the District of Columbia Army National Guard schemed to purchase stolen credit card numbers with Bitcoin and use the accounts to buy goods at military exchanges, among other retailers.

Spcs. Derrick Shelton and James Stewart and former Sgt. Quentin Stewart allegedly used Bitcoin, a digital currency not backed by any government, to buy the numbers from foreign websites, according to a DOJ news release. The men allegedly used encoding devices to transfer the numbers to new credit cards, then bought luxury items, electronics and other goods from exchanges and other retail outlets.

The purchases took place between July 2014 and May 2015, prosecutors say. Spc. Vincent Grant faces a separate indictment under similar allegations, starting the same month but ending in April 2015.

All of the accused but Grant could face up to 20 years in prison if convicted on wire fraud and conspiracy charges; Grant's charged with conspiring to commit access device fraud and could be jailed for 7.5 years if convicted. All four also face aggravated identity theft charges, which carry a two-year minimum sentence.

The men appeared in court last week, and all but Quentin Stewart were released under pre-trial supervision. The former sergeant was scheduled to appear at a detention hearing Tuesday afternoon in Greenbelt, Maryland.