A Middle Eastern man who set himself on fire outside the White House on Monday is a disgruntled FBI informer, the Washington Post newspaper has said.
The man was restrained after setting fire to himself
The daily said the man had threatened to kill himself because the FBI had broken promises involving money, citizenship and identity protection.
The man, who the paper named as Mohamed Alanssi, 52, had been discussing his work with journalists, it said.
He is in a critical condition after receiving burns to 30% of his body.
But his life does not appear to be in danger.
He approached a guardhouse outside the White House soon after 1400 (1900 GMT) on Monday and asked for a note to be delivered to President George W Bush.
After being turned away, he set fire to his jacket with a lighter. Secret service officers managed to douse the flames.
The FBI has declined to comment on the man's identity, saying it did not have a policy on revealing witnesses or co-operators.
Mr Alanssi, a Yemeni, told the newspaper of his plans to kill himself by phone and fax shortly before going to the White House.
He said he would not testify in a key terror trial until he had been to Yemen to see his wife, who was sick with stomach cancer.
"Why you don't care about my life and my family's life?" he wrote in what was described by the Washington Post as a letter to an FBI agent handling his case.
"Once I testify, my family will be killed in Yemen. Me too, I will be a dead man."
Mr Alanssi said in a series of interviews for the newspaper that he had offered information on alleged financiers of the al-Qaeda terror network shortly after the 11 September 2001 attacks on the US and quickly became a major informant.
He said some agents had promised him that he would become a millionaire and be given permanent residence in the US.
But he had only received $100,000 and could not afford to pay medical bills for a recent operation.
The US authorities were withholding his passport until he gave testimony, he said.
In an apparently unrelated incident, another man was detained several hours later after jumping over a fence on the north side of the White House grounds.