Visas were issued to 105 foreign men who should have been prevented from entering the United States because their names appeared on government lists of suspected terrorists, congressional investigators have found.

The visas have since been revoked, but it is possible that some or all of the men were able to enter the United States, officials said. The General Accounting Office, which initiated the probe, is attempting to determine their whereabouts, according to congressional sources familiar with the case.

Under a security system first created in November 2001 called "Visas Condor," State Department applications for visas to enter the United States from certain national groups were to be checked against possible terrorist names in FBI and CIA databases. Men in these groups were aged between 16 and 45, and had to wait up to 30 days for the check before a visa could be issued.

However, the GAO found, until recently the name check system did not work properly as responsibility for it shifted between the Justice Department and FBI, the CIA, the State Department and the multiagency Foreign Terrorist Tracking Task Force formed by President Bush in October 2001.

Few names initially forwarded by the State Department , known as "cables," were checked by either the CIA or FBI, congressional investigators said.

By April 2002, when the terror task force assumed control of the system, the FBI had a backlog of some 8,000 unchecked names from the State Department. Of the 38,000 "Condor" applications subsequently processed through Aug. 1, 2002, about 280 names turned up on the anti-terrorism lists.

The State Department was given a refusal recommendation for 200 visa applicants, but that came after the 30-day hold had expired -- meaning the visas had already been issued. Because of mispelled or duplicate names, GAO officials now believe these visas were actually issued to about 105 men whose names appear on the anti-terror lists.

In many cases, U.S. officials say the refusal recommendation was made simply because there wasn't enough information available about the applicant. But it remains possible that some of the men had real terrorist connections.

Much of the information about the situation was made public last month in a GAO report addressing broader visa questions, but it was largely overlooked. The Chicago Tribune reported on the matter in Tuesday's editions.

Justice Department officials had no immediate comment Tuesday, but in a response to the GAO report a senior official said the FBI and the terror task force have taken steps to eliminate the backlog of names and work more closely with the State Department on streamlining the process.

Under another change made in September, the FBI has initial authority to check the names, then forwards those with a possible match to the State Department -- which then has the CIA do another screening for terrorist connections.

"We are confident that our handling of Condor cables will remain responsive and timely, without sacrificing security," wrote Robert Diegelman, acting assistant attorney general for administration.

State Department officials hope to reduce review time for the Condor applications for those with no FBI records to 10 days or less.