A top US government scientist who helped investigate a series of deadly anthrax attacks in 2001 has died from an apparent suicide, just as the Justice Department was about to file criminal charges against him for the anthrax attacks, the Los Angeles Times reported.

The man was identified as Bruce Ivins, 62, who had worked for the past 18 years at the government’s elite biodefense research laboratories at Detrick, Md.

People familiar with Ivins said the man had been informed of his impending prosecution, his death and with the FBI investigation.

Ivins had played a central role in research to improve anthrax vaccines by preparing anthrax formulations used in experiments on animals. Ivins had also helped the FBI analyze the powdery material recovered from one of the anthrax-tainted envelopes sent to a U.S. senator’s Washington office.

Ivins died Tuesday at Frederick Memorial Hospital in Maryland. According to the Times, a source close to him who declined to be identified out of concern that he would be harassed by the FBI, said he had ingested a massive dose of prescription Tylenol mixed with codeine.

“People here are pretty shook up about it,” Caree Vander Linden, a spokeswoman for the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID) announced his death in an e-mail.

The anthrax mailings that were sent to media organizations and politicians shortly after the September 11, 2001 attacks killed five people – one of them was a postal worker in the mailroom of the New York Post –, shut down a Senate office building and spread fear of further terrorism. Seventeen people become ill but they recovered after treatment.