Secretary of State Colin Powell decided to award the tipster $15 million each for information that led authorities to Odai and Qusai's hideout - a total of $30 million, the largest award ever made under the reward program.
The brothers were killed by TOW missiles fired into the villa in the northern city of Mosul where they had been hiding.
The U.S. government's policy is not to publicly identify informants.
But neighbors of Sheik Nawaf al-Zaydan Muhhamad, an Iraqi with ties to Saddam Hussein, have blamed him for tipping off coalition forces that the ousted Iraqi leader's sons Odai and Qusai were staying with him and his family.
They said they became suspicious of the sheik when his wife and their four daughters left the house early the morning of the shootings and did not return.
Three hours after the women left, U.S. troops walked up to the front door, knocked and asked all those inside to come out. Muhhamad and his only son, Shalan, left with their hands on their heads, neighbors said. Coalition forces took them away.
State Department spokesman Richard Boucher said the next U.S. goal is to get Saddam himself. A $25 million reward has been posted for his capture.
The deposed dictator has so far evaded capture, though several others of his inner circle have been apprehended or killed. Several audiotapes have surfaced of a man purporting to be Saddam inciting attacks on U.S. forces — and CIA experts say many of the tapes probably do carry Saddam's voice.
American officials acknowledge that some Saddam loyalists are emboldened to attack U.S. forces because their former leader remains at large.