San Diego: A US Marine whose murder conviction was recently overturned was released on Monday after serving four years in prison for a major Iraqi war crimes case, his lawyer said.

The overturning of the conviction and the Marine's subsequent release is a major blow to the government's efforts to prosecute Iraqi war crimes.

Prosecutors say Sgt. Lawrence Hutchins III led a squad of seven troops who killed a 52-year-old man in the Iraqi village of Hamdania in 2006, and then planted a shovel and AK-47 to make it appear that he was an insurgent.

A military court in Washington in April ruled Hutchins was not given a fair trial because his lead defense lawyer left the case shortly before his 2007 trial.

The Navy is appealing and has sent the case to the US Court of Appeals for the Armed Forces, which can either affirm or overturn the Washington court's ruling.

Hutchins says he was not with his squad at the time.

An emotional Hutchins vowed to be the best Marine he could be while he waits for the US Court of Appeals for the Armed Forces to review his case, defense lawyer Babu Kaza told The Associated Press on Monday after leaving the closed hearing at Camp Pendleton.

"He's packing his things right now," Kaza said. "He told me there are no words to describe what he is feeling after four years.

"He's looking forward to calling his family not from jail for the first time in a long time."