A law enforcement official, speaking on condition of anonymity Wednesday, said the request was sent by e-mail on Aug. 1, a day before LSU placed Hatfill on administrative leave as director of its National Center for Biomedical Research and Training.
The center receives most of its funding from the Justice Department, according to an LSU official.
LSU Chancellor Mark A. Emmert made no mention of the Justice Department's request when he issued a statement Tuesday announcing Hatfill's firing.
"The university is making no judgment as to Dr. Hatfill's guilt or innocence regarding the FBI investigation," Emmert said.
"Our ultimate concerns are the ability of the university to fulfill its role and mission as a land-grant university," he said. "In considering all of these objectives, I have concluded that it is clearly in the best interest of LSU to terminate this relationship."
The university had no immediate comment Wednesday when asked about the Justice Department's request.
Hatfill spokesman Pat Clawson said the university called Hatfill's attorneys Tuesday afternoon and told him of their decision to fire him. No explanation was given.
In a statement Tuesday, Hatfill blamed the FBI's investigation for his firing.
"My life has been completely and utterly destroyed by (Attorney General) John Ashcroft and the FBI," Hatfill said. "I do not understand why they are doing this to me. My professional reputation is in tatters. All I have left are my savings and they will be exhausted soon because of my legal bills."
Five people were killed by anthrax-laced letters sent through the mail last fall.
The FBI has identified Hatfill as "person of interest" in its investigation but says he is no more or less important than about 30 fellow scientists and researchers with the expertise and opportunity to conduct the attacks.
However, Hatfill has been treated differently. FBI and Postal Service agents wearing protective gloves searched his apartment in Frederick, Md., twice, the second time with a search warrant. And his photo was the only one circulated last month in the Princeton, N.J., neighborhood where investigators believe the anthrax letters may have been sent.
Hatfill appeared at two news conferences in the last month to denounce the FBI's investigation.
Hatfill, 48, worked until 1999 for Fort Detrick's Army Medical Research Institute of Infectious Diseases in Maryland, which is the primary custodian of the virulent Ames strain of anthrax found in last fall's deadly letters.
Hatfill and another scientist, Joseph Soukup, commissioned a study of a hypothetical anthrax attack in February 1999 as employees of defense contractor Science Applications International Corp., said Ben Haddad, spokesman for the San Diego-based company.
Before he worked there, Hatfill spent about 15 years in southern Africa, where he earned a string of academic degrees but disturbed colleagues with his right-wing rhetoric and exaggerated stories about his military career.
Hatfill claimed to have served in the U.S. Army in Vietnam and was discharged after his plane was shot down and he broke his back. However, his military record showed that to be false.
He joined the military in 1975, when Vietnam was ending and was discharged in 1978.
By Christopher Newton