A former U.S. Army Special Forces soldier has pleaded guilty to conspiring with four others to steal $200,000 in government intended for Afghanistan mission and now faces up to 15 years prison, federal prosecutors said.

Former Sergeant First Class William Chamberlain, 46, pleaded guilty to conspiracy and receiving stolen government property in federal court in North Carolina on Monday after having fought the charges for years, prosecutors said.

Four other soldiers, who like Chamberlain were from the 3rd Special Forces Group at Fort Bragg in North Carolina and served in Afghanistan, pleaded guilty in 2014 while Chamberlain planned to defend himself at trial.

After Chamberlain argued that he needed access to classified information for his defense, a judge eventually ruled against him, finding that the classified information was not helpful to his defense, according to a statement from the U.S. Attorney's Office for the Eastern District of North Carolina.

The five defendants were accused of stealing a total of $200,000 between July 2009 and January 2010 while deployed together in Afghanistan.

They had access to classified funds for Special Forces to support counter-terrorism operations, in addition to money intended to buy supplies and support humanitarian projects such as building roads, schools and medical clinics, prosecutors said.

They converted the stolen money into postal money orders bought from military post offices in Afghanistan, sent cash to relatives in the mail or carried cash back home after their deployment, prosecutors said.

When first approached by law enforcement, they falsely claimed they won the cash gambling or brought it with them from the United States.

Chamberlain's defense attorneys were not immediately available for comment.

Chamberlain faces a combined maximum sentence of 15 years in prison, followed by three years of supervised release, a $500,000 fine, mandatory restitution and forfeiture of $40,000, prosecutors said.