An arson car fire, not a crash, killed a woman charged in a fake IDs-for-aliens scheme with possible ties to terrorism, according to an FBI agent's testimony.

Driver's license examiner Katherine Smith, 49, was found burned beyond recognition early Sunday on a rural road 20 miles from her home. Her car, which she bought from one of her co-defendants, had struck a utility pole, authorities said.

FBI agent J. Suzanne Nash testified Wednesday that witnesses told investigators they "noticed flames from the back seat" before Smith's car struck the pole. The agent added that the gas tank was intact.

Authorities said the woman's family last saw her Saturday night. An autopsy and forensic tests on the car are ongoing.

Smith was scheduled to appear in federal court Monday on charges that she sold driver's licenses to five Middle Eastern men, primarily from New York, who did not have proper documentation.

Three of the men — Mostafa Said Abou-Shahin, Abdelmuhsen Mahmid Hammad and Mohammed Fares — were denied bond after a court hearing Wednesday.

Attorneys for the men said they were being punished because of their ethnicity. "They seem to be trying to tie this to Sept. 11," defense attorney Clifton Harviel Jr. said.

But Assistant U.S. Attorney Tim DiScenza said the men, all illegal immigrants, participated in a conspiracy to provide them a "completely false and untraceable identity." He said their motivation could be "further criminal activity, whether fraudulent activity or some other illegal activity."

The other two suspects — Khaled Odtllah and Sakhera Hammad — were being held without bond.

Smith and the five men were arrested Feb. 5 after they left a driver testing station in Memphis. Prosecutors said Smith had processed four driver's license applications that morning based on false information provided by Odtllah.

The Associated Press contributed to this report.