The British attorney general has told the police to look at the part played by Iraqi President Saddam Hussein in hostage-taking during the Gulf War, although he saw little prospect of a conviction.
Lord Williams has passed on to police information gathered by Indict, a London- based organisation which investigates war crimes and crimes against humanity committed by the Iraqi regime.
"The attorney general has concluded in respect of Saddam Hussein that there is currently no realistic prospect of a conviction," a government official told Reuters.
"However there is scope for further inquiries to be carried out and in the circumstances it is proper for the attorney general to report the matter to the police, which he has done."
More than 4,500 Britons and thousands of citizens from other countries were taken hostage in Kuwait and Iraq at the start of the Gulf War in 1990, Indict said. Some were used as human shields to deter allied attacks.
The group believes that Saddam and Iraqi Deputy Prime Minister Tariq Aziz could be culpable for their alleged role in the taking of hostages and gave "extensive files" to Mr Williams.
They included signed witness statements, authenticated command documents and corroborating evidence including diaries, photographs and audio-visual material.
"We very much look forward to working with Scotland Yard detectives to ensure that any possible technical or evidential obstacles to moving swiftly towards an indictment are removed - hopefully in the next few months," Labour politician Ann Clwyd, chair of Indict, said in a statement.
But Williams held out little hope for the case, noting that as a head of state, Saddam has immunity from a criminal prosecution. His aide added that the evidence, as it stood, was too thin to offer a real prospect of conviction.
Indict argued that Britain's initial decision to strip former Chilean dictator Augusto Pinochet of immunity for human rights abuses could set a precedent.
"We are confident that those who commit such crimes can and will be brought to book," Ms Clwyd said.
"We are aware that these crimes, though awful, pale in comparison to the crimes the regime is still perpetrating against the Iraqi people. Many of the hostages were subjected to appalling suffering, physical abuse and mental torture."