The evidence shows that Chalabi - who was once seen as the man likely to lead Iraq by White House and Pentagon officials - personally gave Iranian intelligence officers information so sensitive that if revealed it could, quote, "get Americans killed." The evidence is said to be "rock solid."
Sources have told Stahl a high-level investigation is under way into who in the U.S. government gave Chalabi such sensitive information in the first place.
In addition, sources told Stahl that one of Chalabi's closest confidantes — a senior member of his organization, the Iraqi national congress — is believed to have been recruited by Iran's intelligence agency, the Ministry of Information and Security (MOIS) — and is on their payroll.
Chalabi has denied passing any information to Iran.
The revelations about the former exile came on a day that saw Iraqi police backed by U.S. troops raid Chalabi's Baghdad home and offices.
American soldiers and armed U.S. civilians could be seen milling about Chalabi's compound in the city's fashionable Mansour district. Some people could be seen loading boxes into vehicles. Aides said documents and computers were seized without warrants.
A senior coalition official said several people were arrested and that arrest warrants were issued for "up to 15 people" on allegations of "fraud, kidnapping and associated matters."
Chalabi supporters suggested that the raid was politically motivated bid to intimidate the former exile, who has become extremely vocal in his criticism of Washington.
At a press conference after the raid, Chalabi lashed out at the ruling Coalition Provisional Authority, complaining it was coddling former members of Saddam's Baath Party and treating Iraqis badly.
"I am America's best friend in Iraq," Chalabi said. "If the CPA finds it necessary to direct an armed attack against my home, you can see the state of relations between the CPA and the Iraqi people."
The raid was a symbol of how far Chalabi's stock has fallen in the eyes of U.S. officials.
In exile, Chalabi's U.S.-financed Iraqi National Congress provided intelligence information on Saddam Hussein's Iraq.
Prior to the U.S. invasion of Iraq, Chalabi produced a string of defectors whose stories suggested that Saddam posed an imminent threat to the United States because of his weapons of mass destruction.
A key claim came from a Chalabi-sponsored defector who told U.S. intelligence that in order to evade U.N. inspectors, Saddam put his biological weapons labs in trucks.
The assertion that Saddam had mobile weapons labs was a major feature of Secretary of State Colin Powell's speech to the U.N. on why military action needed to be taken against Iraq.
"We know that Iraq has at least seven of these mobile biological agent factories. Ladies and gentlemen, these are sophisticated facilities. For example, they can produce anthrax and botulinum toxin. In fact, they can produce enough dry biological agent in a single month to kill thousands upon thousands of people," Powell said.
The flow of information caused Chalabi's star to rise in White House and Pentagon circles, despite some warning signs about his reliability.
For example, Chalabi, a former banker, was convicted of fraud in absentia in Jordan in 1992 in a banking scandal and sentenced to 22 years in jail. He has denied any wrongdoing.
Ironically enough, Chalabi's downfall began with an action he had enthusiastically supported: the U.S. invasion of Iraq.
No weapons of mass destruction - or mobile weapons labs - were found. Asreported, a postwar analysis by the government of Chalabi's defectors has found that many of them exaggerated - and that their information about weapons of mass destruction and Saddam's links to Al Qaeda was wrong.
In an interview with, Chalabi minimized the importance of the defector who told of the mobile weapons labs.
"What he said is that these are mobile biological labs. He did not say that they are weapons factories. There's a big difference," Chalabi said.
Chalabi, who had returned to Iraq with a private army of 700 "freedom fighters" following the invasion, began to lose favor with U.S. officials as it became increasingly clear that much of information he supplied was suspect.
Chalabi holds a seat on the Iraqi Governing Council, but he has been unable to build a base of popular support with the Iraqi people.
The New York Times and the Washington Post report that Chalabi has been feuding with L. Paul Bremer, the American civilian administrator in Iraq. The Times quoted Chalabi aides as saying the former exile's relationship with Bremer was so bad that he skipped Governing Council meetings that Bremer attended.
Earlier this week, the U.S. ended the $340,000 monthly payment it was making to Chalabi's Iraqi National Congress. That action was followed by the raid on his Baghdad home.