A man described as a "person of interest" in the US anthrax attack investigation helped the US Government build a mobile germ lab for training special forces in biological warfare, a US paper has reported.
Five people died in the anthrax attacks
Former US Army scientist and germ warfare expert Dr Steven Hatfill is said to have helped build the lab to train the army's elite Delta Force special operations unit to detect and disarm such facilities in other countries, according to the New York Times.
American forces trained in this laboratory - which was never made fully functional - in the months before the recent US-led conflict in Iraq, US Government officials and experts said.
And officials told the paper that Mr Hatfill's involvement in the project was a major reason for him coming under suspicion in relation to the 2001 anthrax attacks.
Five people died in the attacks when letters laced with deadly anthrax spores were sent to several US politicians and media outlets.
Mr Hatfill has denied any involvement in the attacks and has never been arrested or charged in connection with the crime.
And agents from the Federal Bureau of Investigation examined the unit but found no evidence it had ever been used to produce the biological agent, the paper said.
The training lab is reportedly similar to those the US Government accuses Iraq of possessing, the paper said.
The anthrax attacks caused widespread panic
Mr Hatfill is said to have helped develop the mobile plant while working for a leading contractor with the Pentagon and the Central Intelligence Agency.
The training plant's equipment, officials said, includes fermenting tools, a centrifuge and a mill for grinding clumps of anthrax into the best size for penetrating human lungs.
Dr Hatfill, who worked at the Army Medical Institute of Infectious Diseases at Fort Detrick in the US state of Maryland before joining the contractor, began gathering parts for the unit in 2000.
He also supervised its construction at a metalworking plant on the outskirts of the town of Frederick, where Fort Detrick is based, experts said.
In June, FBI officials drained several ponds in Frederick after equipment which could have been used in the anthrax attacks was found in one of the ponds.
The finding led to a new theory - that the perpetrator assembled the laced letters in a watertight chamber to minimise risk to himself - but no arrests.