WASHINGTON - A top U.S. biodefense researcher apparently committed suicide just as the Justice Department was about to file criminal charges against him in the anthrax mailings that traumatized the nation in the weeks following the Sept. 11, 2001, terrorist attacks, according to a published report.

The scientist, Bruce E. Ivins, 62, who worked for the past 18 years at the government's biodefense labs at Fort Detrick, Md., had been told about the impending prosecution, the Los Angeles Times reported for Friday editions. The laboratory has been at the center of the FBI's investigation of the anthrax attacks, which killed five people.

Ivins died Tuesday at Frederick Memorial Hospital in Maryland. The Times, quoting an unidentified colleague, said the scientist had taken a massive dose of a prescription Tylenol mixed with codeine.

Tom Ivins, a brother of the scientist, told The Associated Press that another of his brothers, Charles, told him Bruce had committed suicide.