WASHINGTON -- US justice authorities released a trove of formerly sealed documents Wednesday hoping to bring to a close the case of the deadliest bio-terror attack in US history, a week after the chief suspect in the 2001 case died from a suicide drug overdose.

The Department of Justice, the Federal Bureau of Investigation and the US Postal Inspection service said the unsealed affidavits were to support obtaining search warrants in relation to the mailings of anthrax-laced letters sent to politicians and journalists that killed five people and sickened 17.

Reports said the Justice Department planned to declare the case solved in the wake of the suicide of Bruce Ivins, 62, a bioscientist who worked in a government lab dealing with anthrax.

The investigation into the case has been heavily criticized for initially fingering an innocent scientist, and for the time it took to find the apparent real culprit.

The anthrax attacks sent fresh panic throughout the country just weeks after the September 11, 2001 Al-Qaeda attacks on Washington and New York.