Ousted Iraqi President Saddam Hussein has been arrested in Iraq, according to unconfirmed reports.
He was detained in his ancestral home town of Tikrit, Iraqi Kurdish leader Jalal Talabani said on the official Iranian news agency IRNA.
The US Defence Department said it had no confirmation of the report.
Saddam Hussein is the most wanted man on the list issued by US authorities but has not been seen since Baghdad fell to US forces in April.
A spokeswoman for US-led coalition forces in Baghdad said that a "very important" announcement would be made at a news conference at 1200 GMT but would not give further details.
Nazem Dabag, representative in Iran of the Patriotic Union of Kurdistan (PUK) also said that Saddam Hussein had been arrested.
Saddam Hussein has been the subject of intensive searches by US-led forces in Iraq but previous attempts to locate him have proved unsuccessful.
On 22 July his sons, Uday and Qusay, were killed in a raid by US forces in the northern city of Mosul.
Former Iraqi President Saddam Hussein is believed to have been captured in a raid near his hometown of Tikrit, U.S. military officials say.
However, the officials in Washington told CNN on Sunday that the identity of the individual, who was one of a number of suspected insurgents caught, was still being confirmed.
The person in U.S. custody was disguised in a fake beard when he was captured in the basement in a Tikrit building, Ahmad Chalabi of the Iraqi National Congress said.
Hours after the word leaked out on the possible capture, there were volleys of what was perceived to be celebratory gunfire in Baghdad.
A coalition news conference in Baghdad, scheduled for 3 p.m (1200 GMT), is expected to shed more light on the status of the Iraqi leader.
A briefing in Madrid by the Iraqi Governing Council president and Spanish foreign minister was also expected shortly.
The raid was based on intelligence that Saddam was at a particular location in the area, the officials said.
Video following that raid -- exclusively shot by CNN's Alphonso Van Marsh -- showed a group of U.S.-led coalition soldiers patting each other on the back -- apparently in celebration -- and taking group photos in front of a military vehicle.
The 66-year-old longtime Iraqi leader was number one on the coalition's 55 most wanted list, and his evasion has been a political sore spot for the U.S. administration.