UN rights experts called Thursday for action and prosecutions to end the secret detention of terror suspects, in which it alleges 66 countries including the United States are involved.

The experts on torture, counter-terrorism and enforced disappearances said the 66 countries they had named in a January report must investigate the covert imprisonment of alleged terror suspects.

The report warned that the "widespread and systematic" secret detentions could pave the way for charges of crimes against humanity against the countries concerned.

It listed 66 countries allegedly involved -- from Ethiopia and Romania to Kosovo, Pakistan and the United States -- and called on governments to prosecute those who ordered such detentions.

In a debate Thursday on the report, the experts urged the UN Human Rights Council to take action.

"We think this is enough evidence that the council should take action," said Manfred Nowak, the UN special rapporteur on torture.

A summary of the debate said "secret detention should be explicitly prohibited along with all other forms of unofficial detention."

"In almost no recent cases have there been any judicial investigations into allegations of secret detentions and practically no one has been brought to justice."

The UN special rapporteur on human rights and counter terrorism, Martin Scheinin, said it was clear from the debate that the issue had not been brushed away despite months of delay.

"I don't think the Human Rights Council can ignore the need for inquiries at domestic level, that will necessarily be part of the package," he told journalists.

The experts noted a shift in attitude in Europe and the US government of President Barack Obama, even though domestic political battles had held up progress since the announced closure of secret CIA prisons.

However there was little promise of action from the United States and other major Western powers as well as countries like Egypt, Syria, Sri Lanka, India and Pakistan, with many contesting the report's allegations as inaccurate.