SPOKANE, Wash. The commercial driver licenses of nearly 100 school bus and truck drivers are being revoked by the Washington state Department of Licensing as part of a mail fraud and conspiracy investigation.

The drivers, mostly from other states, used mail-drop addresses in Spokane, didn't meet state residency requirements, and were part of a scheme involving cheating and paying bribes to a third-party test evaluator, said U.S. Attorney Jim McDevitt.

State Licensing Director Liz Luce credited the FBI with breaking up CDL Consulting, which McDevitt described as a "driver's license mill" that primarily targeted Bosnian immigrants living elsewhere.

Brano Milovanovic and Suad Grebic, both of Spokane, were arrested and five other suspects were being sought on mail fraud and conspiracy charges.

The individuals who got their commercial driver licenses from the Spokane driving school returned to other states where they were re-licensed under reciprocal agreements with Washington.

Luce said she couldn't begin the license revocation process until the investigation became public. And, while her agency could only cancel the contract with the private contractor involved in the fraud scheme, Luce said she was pleased the FBI and U.S. attorney's office were pursuing participants on criminal charges.

Luce said that state budget cutbacks in the 1990s caused the department to lose employees, forcing the agency to hire outside contractors as testers for commercial driver license applicants. "I believe that opened the door," she said.

Applicants can no longer choose their own testers, and state licensing personnel are now doing 60 percent of the test-evaluation work, Luce said.

Interpreters helping CDL applicants with written tests also are more closely screened, she said, after the investigation revealed that interpreters were not only reading the questions but also providing answers.