Weapons scientists wanted by the militants

The two female prisoners at the centre of the hostage storm are believed to be Dr Rihab Rashid Taha and Huda Salih Mahdi Anmash.

The two female prisoners at the centre of the hostage storm are believed to be Dr Rihab Rashid Taha and Huda Salih Mahdi Anmash.

Taha is the scientist believed to have designed Iraq's biological weapons programme. She has become known as "Dr Germ" for helping Iraq use anthrax to make weapons, part of a programme the US claimed was big enough to kill everyone on Earth twice over.

Taha says the weapons were merely a deterrent and that Iraq could never have used them against the US because all the weapons, including 2,200 gallons of anthrax, were destroyed over a decade ago.

She has refused to be interviewed privately by UN weapons inspectors because she says she does not trust them. Taha, a 47-year-old mother who earned a PhD in microbiology from the University of East Anglia, admits producing "biological agents", including botulinum - which makes the tongue swell until it causes the victim to suffocate - and anthrax.

She has also been credited with the creation of haemorrhagic conjunctivitis, which makes its victims' eyes bleed, and gas gangrene, which makes human skin melt. She denies allegations that Iraqi scientists have tested biological weapons on Iranian prisoners.

Anmash, called "Mrs Anthrax" by the Pentagon and Western journalists, was arrested in March 2003 by US officials on suspicion of co-ordinating Saddam Hussein's biological weapons programme, a charge she denies.

She was also one of the few women who was close to the former Iraqi dictator.