Officials are comparing the huge trove of documents to the "Stasi files" on East Germany's secret police. CBS News National Security Correspondent David Martin reports the files, which were captured in April, are only now being fully translated and analyzed.
The files may be used as evidence in war crimes tribunals against the ousted Saddam regime.
There is still no evidence, however, that Iraq possessed the stockpiles of biological and chemical weapons or active biological, chemical or nuclear programs that the Bush administration alleged before the war.
The Wall Street Journal reports the files have sparked an FBI investigation of possible criminal or espionage activity within the United States.
There were already indications of possible connections between Saddam's regime and persons or entities located in the United States.
When Iraq issued its weapons declaration last December, a number of published reports said Iraq listed U.S. companies among those who had provided some material to the regime, although it was not clear whether that material was proscribed, or if the Iraqi assertion was true.
More recently, a suburban Chicago man was arrested in July on charges of serving as an unregistered agent of Saddam's government, including spying on opposition leaders for Iraqi intelligence, federal officials said.
Khaled Abdel-Latif Dumeisi, 60, was arrested based on a dossier found in Baghdad in April and turned over to the FBI.
An official says the documents detail an elaborate network of foreigners who were paid by Iraq — not to spy, but to push for pro-Saddam policies, The Washington Post reports. Sources told the Post the agents included high-ranking officials working in Arab countries and other regions.
According to the Journal, the files may also help flesh out the extent of Saddam's weapons ambitions.
An official says the documents and evidence from U.S. interrogations suggest Iraq received technical assistance from two teams of Yugoslav missile experts and another foreign country that sources would not name.
The help, provided from 2001 to as late as this year, was allegedly aimed at extending the range of Iraq's missile, which was restricted under Security Council resolutions.
The documents also point to negotiations with North Korea to buy long-range missiles, the official says. Iraq made a $10 million down payment in 2002 but Pyongyang said it could not deliver the weapons, according to the Journal.
The Journal, quoting the same official, says evidence indicates Iraq was behind small-scale terrorist attacks against U.S. targets, including one in Asia in 1993 in which no one was injured.
Meanwhile, International Atomic Energy Agency head Mohammed ElBaradei is asking the United States to turn over a classified version of Iraq Survey Group leader David Kay.
Kay told Congress earlier this month that he had seen evidence that Iraq violated Security Council resolutions, hid material from inspectors, planned to build missiles to fly beyond range limits and possessed the capacity to quickly resume biological weapons production.
However, Kay reported no solid evidence of actual biological, chemical or nuclear weapons or active programs to develop them.