The scientist, Bruce E Ivins, 62, who worked for the past 18 years at the government’s biodefense labs at Fort Detrick, Maryland, 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 on 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.

A woman who answered the phone at Charles Ivins’ home in Etowah, North Carolina, refused to wake him and declined to comment on his death. “This is a grieving time,” she said.

A woman who answered the phone at Bruce Ivins’ home in Frederick declined to comment.

Justice Department spokesman Peter Carr and FBI Assistant Director John Miller declined to comment on the report.

Henry S Heine, a scientist who had worked with Ivins on inhalation anthrax research at Fort Detrick, said he and others on their team have testified before a federal grand jury in Washington that has been investigating the anthrax mailings for more than a year.

Heine declined to comment on Ivins’ death.

Norman Covert, a retired Fort Detrick spokesman who served with Ivins on an animal-care and protocol committee, said Ivins was “a very intent guy” at their meetings.

Ivins was the co-author of numerous anthrax studies, including one on a treatment for inhalation anthrax published in the July 7 issue of the journal Antimicrobial Agents and Chemotherapy.

Just last month, the government exonerated another scientist at the Fort Detrick lab, Steven Hatfill, who had been identified by the FBI as a “person of interest” in the anthrax attacks. The government paid Hatfill $5.82 million to settle a lawsuit he filed against the Justice Department in which he claimed the department violated his privacy rights by speaking with reporters about the case.

The Times said federal investigators moved away from Hatfill and concluded Ivins was the culprit after FBI Director Robert Mueller changed leadership of the investigation in 2006.