Eight former aides to Saddam Hussein - including two women accused of making biological weapons - have been released from US custody in Iraq.
Huda Ammash was educated in the US
The freed detainees no longer pose a security threat, a US spokesman said.
They include Huda Salih Mahdi Ammash, nicknamed by the US "Mrs Anthrax" and Rihab Taha, also known as "Dr Germ".
Reports have been circulating of a pre-election deal to free former regime figures in order to appease Iraq's Sunni Arabs, correspondents say.
A US military spokesman in Baghdad said eight detainees "were released as part of an ongoing process for many months in full consultation with the Iraqi government".
"Many were originally held as suspects in possible war crimes and as material witnesses," the spokesman said.
They were released over the weekend after nearly three years in detention.
They have been flown to Jordan, reportedly because of fears for their safety in Iraq, where many former regime figures have been assassinated.
The British-educated Dr Taha and US-educated Mrs Ammash had both been accused by the Bush administration of involvement in Saddam Hussein's banned weapons programme.
Neutralising the threat posed by the former leader's chemical and biological weapons was cited by the US as its prime motive for invading Iraq in 2003.
No such weapons have been found since the invasion.
While the US military maintains only eight figures from Saddam Hussein's government have been released, an Iraqi official quoted by the Associated Press news agency said some 24 prisoners had been set free.
Aseel Tabra, an Iraqi Olympic Committee official and Hossam Mohammed Amin, head of the weapons inspections directorate, are among those released, according to the official quoted by the agency.