A leading human rights group says key evidence in the planned trials of former Iraqi leader Saddam Hussein and other regime officials has been lost or stolen.

In a report issued Thursday, Human Rights Watch accuses U.S.-led military forces in Iraq of "negligence" for failing to safeguard Iraqi government documents and mass grave sites in the country.

The group says people have stolen thousands of documents and damaged some mass graves after the fall of the Iraqi regime last year.

A spokeswoman for the group, Sarah Leah Whitson, says the evidence is crucial to planned trials of Saddam Hussein, who has been charged with war crimes, genocide and crimes against humanity.

She says the information could also help Iraqi families confirm the fate of thousands of people believed to have been killed under the Saddam regime.

Some information for this report provided by AFP, AP.