A key government witness in the trial of four men accused of operating a "sleeper" terrorist cell pleaded guilty Thursday to 10 federal charges of fraud and misuse of a visa, clearing the way for him to testify.

Youssef Hmimssa, 32, could testify next week in the trial that began late last month against four North African men accused of conspiring to provide material support or resources to terrorists. The trial is the first in the United States for an alleged terror cell detected following the Sept. 11 attacks.

The government claims the four defendants attempted to recruit Hmimssa and wanted him to make false documents to get people into the country illegally. Defense lawyers in the terrorism case say Hmimssa is a liar who is trying save himself.

Charges against Hmimssa and the others stem from a raid on a Detroit apartment six days after the Sept. 11, 2001 attacks.

Prosecutors say the raid turned up a day planner that detailed planned attacks on an American air base in Turkey and a hospital in Jordan, as well as a videotape of U.S. landmarks including Disneyland and Las Vegas' MGM Grand Hotel and Casino. Authorities also found fake IDs and documents, including some with Hmimssa's photo.

Defense lawyers have said the tape is an innocuous travel video and that the planner belonged to someone else.

Three of the conspiracy defendants -- Karim Koubriti, 24, Ahmed Hannan, 34, and Farouk Ali-Haimoud, 22 -- were arrested in Detroit at the time of the raid. Hmimssa was arrested later that month in Iowa, and the alleged handler of the cell, Abdel-Ilah Elmardoudi, 37, was arrested in November 2002 in North Carolina.

All of the men are from Morocco except Ali-Haimoud, an Algerian.

Hmimssa used several aliases and faced a variety of federal charges in Michigan, Illinois and Iowa, including fraud, misuse of visas, credit card fraud and conspiracy to obtain Social Security numbers.

Under federal sentencing guidelines, Hmimssa, 32, faces a prison term of between three and four years, after which he probably will be deported to Morocco.