An aspiring Iranian-American filmmaker who has been detained by the U.S. military for nearly two months without being charged was released Sunday, officials said.

Cyrus Kar (search), 44, was taken into custody May 17 near Balad (search) when potential bomb parts were found in a taxi in which he was riding. His family had filed a lawsuit accusing the federal government of violating his civil rights when it continued to hold him after the FBI cleared him of suspicion.

"Kar was detained as an imperative security threat to Iraq," the military said Sunday in a statement. "After his initial questioning, the military notified the FBI, who initiated an investigation to determine if Kar had engaged in terrorist activities."

The U.S. military then convened a review board hearing on July 4 to determine whether Kar was an "enemy combatant (search)."

"Based on the FBI investigation, the testimony of Kar and the witness he called, and other witness statements, the board determined Kar was not an enemy combatant and recommended his release, which was approved," the statement said.

The U.S. military defended its detention of Kar.

"This case highlights the effectiveness of our detainee review process," spokesman Air Force Brig. Gen. Don Alston was quoted as saying in the statement. "We followed well-established procedures and Mr. Kar has now been properly released."

Kar was born in Iran but immigrated to the United States as a child. He served in the Navy and worked in the computer industry before becoming interested in documentary filmmaking.

With help from independent producer Philippe Diaz, Kar began working on a documentary about the ancient Persian king Cyrus the Great (search). He interviewed experts and shot of footage at archaeological sites in Afghanistan and Iran, according to his family and Diaz.