State Department spokesman Richard Boucher said on Thursday that the identity of the recipient would remain a secret.
However, many Iraqis believe he is the owner of the house in which the brothers were hiding in the northern city of Mosul.
Nor would Boucher say whether the informant had requested any type of US protection or relocation.
But he stressed that up to a $25 million reward for information leading to Saddam was still up for grabs.
"It's important ... to show people that we do what we say we're going to do" -- Richard Boucher
Boucher said the actual payment of the reward would be made "very shortly" after details of the transaction were "worked out with the individual in his choice of denominations or transfers."
"It's important ... to show people that we do what we say we're going to do," he said.
"We want to make clear that there are other opportunities for similar sums of money to be paid should other individuals want to come forward with information about Saddam Hussein," Boucher said.
The bounty is the largest-ever awarded by the US "Rewards for Justice" programme, that offers cash for information leading to the capture of wanted terrorists, indicted war criminals and others.
It is 15 times as much as the previous record amount paid - $2 million awarded for information that led to the 1995 capture in Pakistan of Ramzi Yousef, since convicted of the 1993 World Trade Center bombing.
Only Saddam and Osama bin Laden, who also has a $25 million price on his head, have higher rewards posted than for Uday and Qusay.
The two sons were found in a private home in Mosul on July 22 and, along with two others in the house, were killed in a firefight with US forces.