The FBI, plunging full steam into the Iraq intelligence controversy, is conducting a wide-ranging investigation into the forged documents that purported to show that Saddam Hussein's regime was seeking to buy significant quantities of uranium, NEWSWEEK has learned.

The previously undisclosed probe is being conducted by the FBI's Counter-Intelligence Division and, although formally labeled a "preliminary inquiry," is described by knowledgeable sources as active and ongoing.

Only three months ago, FBI director Robert Mueller had brushed aside a request from Sen. Jay Rockefeller, vice chairman of the Senate Intelligence Committee, to probe the Niger documents. Bureau officials concluded then that the forgeries did not appear to be part of a broader disinformation campaign to influence U.S. policy by a foreign intelligence service.

But more recently, the Counter-Intelligence Division, overseen by its aggressive assistant director, David Szady, has revisited the matter--in part after further prodding by Rockefeller's office, three sources tell NEWSWEEK.

Agents have been dispatched to Italy and other foreign countries to look into the murky origins of the documents. In addition, Szady has ordered the questioning of officials at the State Department and the CIA, a particularly awkward development given the longstanding rivalry between the bureau and the agency.

The probe thus injects a new wild card into the mounting controversy over how bogus information gleaned from the documents made its way into President Bush's State of the Union Message.