The jailed Iraqi microbiologist dubbed Mrs Anthrax is seriously ill and should be freed, an Iraqi lawyer has said.
Dr Ammash was also a senior Baath party official
Dr Huda Salih Mahdi Ammash is dying from cancer, according to Badih Aref - who represents imprisoned former Iraqi deputy Prime Minister Tariq Aziz.
The lawyer said his client had asked him to help Dr Ammash, who was in "terrible pain".
She has been treated for cancer before, but US officials said she was regularly checked for signs of a recurrence.
"We have no immediate concerns for her health," a US military officer told the AFP news agency.
Another spokesman insisted the US had "medical care available to take care of any detainee".
Mr Aref said Tariq Aziz passed on the information about Dr Ammash during a meeting.
"When I met Mr Aziz, he told me 'her case is more than important than mine'," Mr Aref said.
"She is always in terrible pain because of cancer, her medical condition is worsening quickly and if she remains like that she will undoubtedly die," the lawyer said.
Mr Aref said Dr Ammash had been treated for breast cancer before her arrest and had now suffered a relapse.
The scientist is one of two high profile Iraqi women arrested by US troops in May 2003 and held at a secret location.
She was one of the few women in Saddam Hussein's inner circle and the only one on the US list of 55 most wanted Iraqis.
She was the only female member of the Iraq Command, the 18-member council that ran the Baath Party, as well as a party regional commander.
However the US-educated microbiologist is best known for her alleged involvement with the weapons of mass destruction programme.
Dubbed "Mrs Anthrax" by Washington, US intelligence services say she masterminded the reconstruction of Iraq's biological weapons facilities after the 1991 Gulf War.
The other high profile Iraqi woman imprisoned by the US is microbiologist Dr Rihab Rashid Taha, who became known as Dr Germ for helping Iraq develop weapons-grade anthrax.