"There's not a single prisoner left there," Deputy Justice Minister Busho Ibrahim told The Associated Press.
The facility has been turned over to Iraqi authorities since it was emptied on Aug. 15, he said.
Iraqi authorities have not decided what they will do with the empty facility, Ibrahim said.
The U.S. military said a transfer of nearly 3,000 detainees from Abu Ghraib to other detention facilities run by the military was planned. But it would not comment on the timing of the transfer.
"We are currently in the process of transferring the Abu Ghraib facility back to the Government of Iraq. For operational security reasons we would prefer not to discuss the actual timing of the operation until it is complete," said Lt. Col. Keir-Kevin Curry, spokesman for detainee operations.
He said the transfer "will allow us to consolidate our effort at fewer sites and improve the conditions for both the coalition guards and the detainees."
Ibrahim said that another detention facility, Fort Suse, in the northern Sulaimaniyah area, will also be emptied and handed over to Iraqi authorities on Sept. 22.
Abu Ghraib came to symbolize American mishandling of prisoners captured in Iraq, both during the U.S.-led invasion three years ago and the fight to subdue the largely Sunni Arab insurgency since then.
Widely publicized photographs of prisoner abuse by American military guards and interrogators at the facility prompted intense global criticism of the U.S. war in Iraq and fueled the insurgency. The scandal led to a wide-scale investigation that resulted in convictions and dismissals against U.S. soldiers.
Abu Ghraib was also a notorious detention center during Saddam Hussein's days, where the former dictator incarcerated his political opponents. Right before the invasion, Saddam released thousands of inmates at the facility, including common criminals, which was seen as a move aimed at spreading chaos after the military attack.
Ibrahim said the detainees at Abu Ghraib were moved to a new $60 million detention facility that has been built as part of Camp Cropper near Baghdad International Airport. Detainees in Fort Suse will be moved to Camp Cropper and Camp Bucca, which is near the southern port of Umm Qasr, he said.
"Abu Ghraib was quite an old place. I used to hear about it since I was 6, I'm now 60," Ibrahim said.
Abu Ghraib, a 280-acre facility, a jumble of top-security buildings and minimum-risk tent cities located along a dusty highway west of the city, has come under repeated attacks from insurgents. In April 2005, a barrage of 28 mortar rounds killed 22 prisoners and injured 91. There were no U.S. deaths in that attack.
U.S. military officials had said they have always had the intention to move detainees from Abu Ghraib because it is in a region susceptible to attacks and was difficult to support logistically.
More than 13,000 detainees are being held at coalition facilities, in Camps Cropper, Bucca, and Fort Suse. Many detainees are awaiting trial, others formal charges.
A committee consisting of U.S. and Iraqi officials from the ministries of human rights, justice and interior has reviewed the cases of more than 30,000 detainees and recommended more than 15,400 for release.