Ousted Iraqi President Saddam Hussein has been captured by US forces in Iraq, the coalition says.
He was found hiding in a cellar in his ancestral hometown of Tikrit, Iraqi official Ahmed Chalabi said.
British Prime Minister Tony Blair has welcomed the news saying it 'removes the shadow' from over Iraq.
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.
Saddam Hussein has been the subject of intensive searches by US-led forces in Iraq but previous attempts to locate him have proved unsuccessful.
People have started celebrating the possible capture of their former president in the streets of Baghdad and the northern Iraqi city of Kirkuk.
The former Iraqi leader was last seen in television footage shot in April at a Baghdad market just before the city fell to US forces in the recent Iraq conflict.
US authorities have offered a $25m reward for information leading to his capture.
On 22 July his sons, Uday and Qusay, were killed in a raid by US forces in the northern city of Mosul.
In October, US officials said they had intelligence indicating Saddam Hussein was hiding in Tikrit.
They said he seemed to be moving around various safe houses with the aid of family members, often in disguise.
Saddam Hussein was born in Tikrit and has a tight network of family and clan ties which permeated all of the regime's main military, security and political institutions while he was in power.
The BBC's Caroline Hawley in Baghdad says it is not clear how US forces will verify that the identity of the man they reportedly have in custody is Saddam Hussein and not one of his doubles.
Its not the size of the army, but the fury of its onslaught