Other candidates from a record field of 156 could be the former US president Jimmy Carter, or a religious or intellectual leader working to heal rifts between Muslims, Christians and Jews - the moral antithesis of an Osama bin Laden.

But experts say there is no clear favourite for the $1 million prize to be announced by the five-member committee on 11 October. Last year, by contrast, most bets were correctly on the United Nations and its secretary general, Kofi Annan.

"They would love to find a good Muslim," said Stein Toennesson, head of the International Peace Research Institute in Oslo.

He said Mr Karzai was a possible winner but that he might be viewed as too much of a US puppet after the defeat of the Taleban. Mr Karzai could, however, be a popular choice abroad and help nudge Afghanistan towards a durable peace.

Sverre Lodgaard, director of the Norwegian Institute of International Affairs, said Mr Carter seemed the clearest candidate in a year with no front-runners. Mr Carter came close to sharing the 1978 prize with the Egyptian president Anwar Sadat and the Israeli prime minister Menachim Begin after he brokered their peace deal. He has been repeatedly nominated for working for peace from North Korea to Haiti.

But others dismissed Mr Carter. "It would be a capitulation, a lack of ideas. It would be rather embarrassing," said Nils Morten Udgaard, foreign editor of Aftenposten, Norway’s main conservative daily.

The committee will have a last meeting on 3 October.

Udgaard said a prize to Mr Karzai would be surprising and said the committee might want to find a "Muslim intellectual preaching understanding and not jihad ... they will have a difficult choice this year".

Chinese dissidents could be favoured because Geir Lundestad, the director of the Norwegian Nobel Institute, said last year that the committee should speak out "sooner rather than later" against China’s lack of human rights and democracy.

Among possible nominees are the Tiananmen Mothers, who lost sons or other loved ones in the 1989 massacre in Beijing. The spiritual movement Falun Gong has also been nominated.

Mr Toennesson said that the politically left-leaning committee might seek to snub US President George Bush’s unilateralist shift by promoting the environment or the global war-crimes court system. The International Criminal Tribunal for former Yugoslavia, now trying the former president Slobodan Milosevic, could be among candidates after Mr Bush opposed the permanent International Criminal Court.

An environmental group might also win after Mr Bush ditched the Kyoto accord on global warming.