It has been described by many as one of the 'western worlds' biggest embarassments.

Now there are reports that a permanent prison is being built at the Guantanamo Bay detention centre where hundreds of alleged terrorist suspects, including nine Britons, are held.

The development of the hard-walled site, which will hold about 100 inmates, has fuelled speculation that suspects could be detained for many more years without charge.

Until now, the 660 prisoners most of whom were detained during the Afghanistan conflict - have been held in corrugated metal units at the base on the southern tip of Cuba.

The move comes just weeks after a senior Red Cross official labelled Guantanamo Bay "a legal black hole".

Christophe Girod, head of the ICRC delegation in Washington, said, "The point is that the US authorities have put the internees in Guantanamo beyond the law."

Military tribunals will hear the cases against the inmates who have been labelled unlawful combatants rather than prisoners of war by the US.

An Australian lawyer representing some of the suspects has also claimed suspects have been tortured.

US-based Richard Bourke, who has been working for almost two years on behalf of dozens of detainees at Guantanamo Bay, said American military officials were using old-fashioned torture techniques to force confessions out of prisoners.

Bourke said the methods "clearly" fell under the definition of torture under international conventions.

"They are engaging in good old-fashioned torture, as people would have understood it in the Dark Ages," he said.

Bourke told ABC radio in Australia that his claims were based on reports leaked by US military personnel and from descriptions by some detainees.

"One of the detainees had described being taken out and tied to a post and having rubber bullets fired at them. They were being made to kneel in the sun until they collapsed," he said.

Media reports that many detainees have attempted suicide and are suffering mental health problems backed up claims of harsh treatment, he said.

The new 100-capacity prison block, which will be completed by next spring, could house those who are sentenced to prison terms by the tribunals.

Officials told the New York Times that there were no plans to build an execution chamber at the US Navy site.

However, we may never know the truth because US military officials recently imposed strict reporting limits on the first journalists to go to the camp.

The reporters were required to sign "ground rules" for coverage that banned questions about the investigations on pain of being removed from the US Navy camp.

Asked why journalists were being warned of consequences if they ask questions, Army Lt. Col. Pamela Hart said, "Why ask a question that you're not going to get an answer to?"

Hart, a spokeswoman for the detention mission, said the ground rules helped in "protecting the integrity of the investigation."

"The ground rules are because we have an ongoing operation. ... To discuss details about ongoing investigations may prejudice the outcome," she said.

Among the nine Britons being held at the site are Moazzam Begg, from Birmingham, and Feroz Abbasi, from south London.

In July Prime Minister Tony Blair urged George Bush to suspend military tribunals for the two men