The U.S. handed over all of the remaining detainees in U.S. custody in Iraq Tuesday, except for a Lebanese Hezbollah commander linked to the death of four American troops, Iraqi and American officials said.
The prisoner transfer marks another step toward the American military's withdrawal from Iraq, as it plans for all U.S. troops to be out of the country by the end of this year.
It still leaves the contentious issue of what to do with a prisoner that many in the U.S. worry will walk free if he's handed over to the Iraqi government.
Iraqi Deputy Justice Minister Busho Ibrahim said 37 detainees were transferred to Iraqi custody Tuesday morning.
A U.S. military official confirmed all the remaining prisoners were transferred with the exception of Hezbollah operative Ali Mussa Daqduq, who he said is still in American custody while the U.S. weighs his situation.
The official spoke on condition of anonymity due to the sensitivity of the issue.
Washington is worried that if Daqduq is transferred to Iraqi custody, he'll be released. The Lebanese militant from that country's Shiite Hezbollah guerrilla group was captured in 2007 in the Iraqi Shiite holy city of Karbala.
Hezbollah is an Iranian-backed militant group that the U.S. has branded a terrorist organization.
Daqduq is accused of working with Iranian agents to train Shiite militias who targeted American soldiers in Iraq. He was linked to a brazen 2007 raid in which four American soldiers were abducted and killed in Karbala.
He has been dubbed by a former CIA officer as "the worst of the worst," and U.S. officials are worried that if he is transferred to Iraqi custody, he could escape from Iraq's troubled prison system or simply be allowed to walk free.
The Obama administration is considering what to do with the Hezbollah operative and has been weighing whether to transfer him to the United States for a military trial. That would likely require the approval of the Iraqi government.
Under the security agreement, all detainees in U.S. custody must be transferred to Iraqi authorities by the end of this year as part of plans to end the American military presence in Iraq by 2012.
At the height of the conflict, the U.S. military held as many as 90,000 prisoners. Those numbers have slowly dwindled as the U.S. has either released or transferred to Iraqi custody thousands of the detainees.
The U.S. now has just under 20,000 troops in Iraq on eight bases. U.S. and Iraqi officials negotiated for months about whether to keep a residual force of American troops in the country past the deadline, but those plans were scuttled when Iraq refused to grant the troops the legal protections the U.S. government required.