U.S. military holding 'Dr. Germ,' 'Mrs. Anthrax'
But it says no women in two prisons named by militants
(CNN) -- Islamist militants who beheaded two American contractors in Iraq say they will kill the third hostage -- a Briton captured with the two Americans -- unless Iraqi women are released from two American prisons in the country.
The U.S. military says women are not held at the two prisons named -- the notorious Abu Ghraib in Baghdad and Umm Qasr near Basra -- cited by the group known as Unification and Jihad but has acknowledged it is holding two female "security prisoners" elsewhere.
They are Dr. Rihab Rashid Taha, a scientist whom some American officials called "Dr. Germ" for helping Iraq make weapons out of anthrax, and Huda Salih Mahdi Ammash, a biological weapons researcher known as "Mrs. Anthrax."
When the women were seized in May 2003, U.S. officials told CNN they were optimistic that Taha's apprehension would prove to be extremely significant, given the scope of her work with biological agents.
Taha was educated in Britain at the University of East Anglia, where she completed a Ph.D. in plant toxins between 1980 and 1984, according to the UK's Press Association.
She later returned to Iraq and took charge if the country's major biological facilities in the late 1980s, PA said.
Officials said they believed she would help uncover evidence of Iraq's suspected recent chemical and biological weapons program.
As yet no evidence of Iraqi weapons of mass destruction -- used by the U.S. and British governments to justify the invasion of Iraq in March 2003 -- has been found.
Although she was not in the deck of playing cards handed out to U.S. troops, Taha was No. 197 on the list of most wanted Iraqis and was regarded by U.S. intelligence sources as extremely knowledgeable and competent with biological agents.
Close to Saddam
U.S. officials accused Ammash of overseeing Iraq's suspected biowarfare research programs -- a claim she denied. Pentagon sources referred to her by the nickname "Mrs. Anthrax."
Months before the war, she appeared in videotapes of Saddam meeting with his war Cabinet.
Ammash was No. 53 on the U.S. list of 55 most wanted Iraqis and the five of hearts in the deck.
The former head of Iraq's biowarfare program told CNN that Ammash did not play a significant role in the nation's weapons programs, but did play an administrative role.
A scientist told CNN that Ammash ran a medical testing program in recent years but did not put much time into it.
Officially, Ammash oversaw Iraq's youth activities and the trade bureau.
Ammash was one of the few women close to Saddam and was promoted in 2001 to the Baathist National Command.
Born in 1953, Ammash received a masters degree in microbiology from Texas Women's University in Denton, Texas. She obtained a doctorate from the University of Missouri-Columbia.