Paul Reynolds BBC News Online world affairs correspondent

The US Government and Iraqi opposition groups are discussing whether Saddam Hussein and his top aides - known as the "dirty dozen" - should be put on trial for war crimes in Iraq itself if the regime is overthrown and they are captured.

The debate is further evidence of the way in which American thinking is being projected forward to consideration of a post Saddam Hussein Iraq.

There is a growing consensus that the best solution would be for Saddam Hussein to be tried in Iraq under Iraqi law.

Charles Forest, Indict

Officially, the US position, laid out in a State Department document in 1999, is that "The goal of the United States is to see Saddam Hussein indicted by an international tribunal."

But until recently, the type of tribunal envisaged remained vague.

Charles Forest, director of Indict - a London-based group (funded partly by the US State Department) which is gathering evidence for a war crimes trial - said: "There is a growing consensus that the best solution would be for Saddam Hussein to be tried in Iraq under Iraqi law."

International judges

He said there could be an international element, with foreign judges sitting alongside Iraqi judges in a special court. This would help avoid any impression that Iraqis who suffered under Saddam were taking revenge. And Iraqi law would have to be changed first.

"At the moment, Saddam Hussein and the top leadership are immune under Iraqi law," he said.

The charges would include the use of poison gas, the execution of prisoners of war, the campaign against the Kurds in the 1980s and against marsh Arabs and crimes committed during the invasion and occupation of Kuwait

According to Mr Forest, an American lawyer who worked with the UN in Bosnia, there is a little chance that a special International Tribunal would be convened to try Saddam Hussein in, say, The Hague, where the former Yugoslav leader Slobodan Milosovic is now on trial.

This is because the International Court has now been set up - and the UN might not want to undermine that, even though the ICC jurisdiction does not cover events before 1 July 2002.

Indict Saddam Hussein

Indict's Chair, the MP Ann Clwyd who also heads the UK All-Party Human Rights Group, doubts however if such a plan would work and she is calling for European governments, including the British, to bring in indictments against Saddam Hussein and other Iraqi leaders now.

Ali Hasan al-Majid is a key Saddam ally and former 'governor' of Kuwait

"We have built up cases against the top 10 in the Iraqi leadership", she said "We are waiting to hear from the UK Attorney-General whether Britain will indict Saddam Hussein and Tariq Aziz (the Iraqi deputy prime minister) for holding hostages after the invasion of Kuwait".

Indict and the Iraq Foundation in the United States have gathered evidence from witnesses and documents which would provide the basis of any prosecution.

One of the biggest collections of documents was captured by the Kurds during their uprising in northern Iraq in 1991. These papers have been deposited in the University of Colorado.

Charles Forest of Indict says they provide clear evidence that Saddam Hussein and his aides, especially Saddam's cousin Ali Hasan a-Majid, ordered the deaths of entire families and villages.

Ali Hasan is known as "Chemical Ali" to Iraqi exiles because of his alleged role in the chemical attack on Halabja, a Kurdish village.