Ancient computers in a public library have been seized in the hope that they may hold clues about the 2001 letters and the Army scientist accused of mailing them, the FBI said Thursday.

Bruce Ivins used the computers for about 90 minutes on July 24 to read e-mail and review a Web site dedicated to the anthrax investigation. The FBI say that Ivins killed himself a few days later and he is believed to have sent letters packed with anthrax which killed five and made 17 others sick.

Agents removed the computers last Thursday from the C. Burr Artz Library in downtown Frederick, Maryland and will search them for any sign of relevant communications including writings identifying a plan to kill witnesses, or perhaps suicide letters.

Apparently, Ivins went to the library on the day he was released from a two-week psychiatric hospital stay. Still, given the amount of use the computers have had over the last seven years, finding a single letter or data on a hard-drive would be like trying to find a needle in a haystack.