The U.S. army has withdrawn charges against a U.S. soldier accused of conspiracy to commit murder, for an incident in 2007 in Baghdad, because of newly found evidence, it said on Tuesday from Germany.

Sergeant Charles Quigley still faces non-judicial punishment for failing to report the incident, the 7th Army Joint Multinational Training Command in Grafenwoehr said in a statement.

Four Iraqi detainees, unarmed, handcuffed and blindfolded, are alleged to have been shot dead near a canal in Baghdad in March or April 2007.

Three soldiers have already been convicted of crimes linked to their involvement in the incident and two more -- Sergeant First Class Joseph P. Mayo and Master Sergeant John E. Hatley -- face trial in the coming months at the Rose Barracks Courthouse in Vilseck in southern Germany, the army said.