There are now 680 men and boys in the Cuban camp which has provoked outrage among human rights groups since it was opened.
Last week the US announced that six of the captives would stand trial in a military tribunal with the personal approval of President George W Bush.
Now the US National Association of Criminal Defence Lawyers (NACDL) president, Lawrence Goldman, has criticised the tribunal set-up saying there would be no confidentiality between lawyers and clients - held to be a basic tenet of legal representation.
This will make it virtually impossible for a trial to be fair, says Goldman.
The NACDL president told ABC radio that the US administration had made it clear all conversations between detainees and their lawyers would be recorded.
"I would be very nervous if I were a client, to tell my lawyer certain facts that I think could be harmful to my case or even helpful to my case," he said. "So it becomes an almost impossible situation."
"I would not walk into these trials as a defence lawyer..."
Goldman said the military court was likely to be biased because the judges, who would probably be senior military officers, would find it difficult to acquit someone whom the President of the United States had recommended for trial.
"I would not walk into these trials as a defence lawyer with the confidence that my client would get a fair shake," he said.
NACDL highlighted the case of Australian-born Taliban fighter David Hicks, who is being held by US authorities as a suspected al-Qaeda member, one of more than 680 detainees.
Hicks, who was named last week as one of an initial group of six detainees eligible to face a US military tribunal, does not yet have a military-assigned lawyer for his defence.
An 80 year old goatherd eventually
released from detention after no
charge, trial or apology
He has repeatedly denied links to al-Qaeda network, though he admits fighting with Taliban.
His family has appointed a civilian legal team on his behalf, although it appears US authorities may not allow lawyers access to the trial.
The former poultry process worker from Adelaide has been in US custody at Guantanamo Bay, Cuba, since he was captured fighting with Taliban by US troops in Afghanistan in November 2001.
Those unfortunate enough to be taken to Camp X-Ray and Camp Delta in the US-occupied colony on Cuba can expect to be:
- Held without charge
- Denied the protection of the Geneva Convention by their military captors
- Refused the right to legal counsel
- Tried in secret by military tribunal with no right to appeal and subsequent execution.
There have been at least 28 suicide attempts among the detainees. All captives are only allowed out of their cages to shower for five minutes and exercise for 10 minutes once a week.
More than 40 detainees have been released, all of whom were in the wrong place at the wrong time, including two goat farmers in their mid-80s.
Three boys aged between 13 and 15 are among inmates at the internationally condemned camp, a US military official told the British Guardian newspaper.
The US continues to view captives as "enemy combatants" - a term it has used to argue that the Geneva Conventions do not apply to the inmates, who have not been charged with any crimes.