Qatar's minister of justice from 1996 to 1997, Dr Najeeb bin Muhammad Ahmad al-Nauimi, also says secret telephone calls have taken place between certain selected prisoners and their families.
The US has been tight-lipped about the exact number of detainees; reports about Guantanamo normally reckon 660 captives are at the Camp Delta detention centre. But al-Nauimi disputes this.
"There are more than 660," he says, "because many others were arrested after Afghanistan. Some of them are 'very classified'. We believe there are more than 700, up to about 800."
He says the number of inmates has been boosted by the transfer of people detained in various countries after the 2001 Afghanistan war.
Al-Nauimi has been acting as legal counsel for 96 families of detainees over the past two years. He is also chairman of the Committee for the Defence of the Detainees at Guantanamo, an organisation he co-founded to provide legal assistance to the prisoners and their families.
The former justice minister will be assisting the Pentagon-appointed US lawyers at the military tribunal for several prisoners expected at the end of March, three of whose families he has advised and represented.
Speaking at his home in Doha, Qatar, al-Nuaimi said he knew of at least two families – both Saudi – who received secret telephone calls from relatives at Guantanamo.
Those calls lasted 40 to 50 minutes, he says, and took place in November 2002 during the Muslim month of Ramadan.
Families are barred from visiting
prisoners in Guantanamo Bay
The two families said they were told by the prisoners to keep the communication confidential – suggesting others have also been contacted, but are afraid to reveal the calls, he says.
Al-Nauimi says prisoners deemed "cooperative and helpful" were allowed to ring their families, partly to encourage them to give more information.
But when he told his Pentagon contacts about the calls, an official said: "No, that never happened."
"I told him exactly when the calls were made," says al-Nauimi. "I told them, 'I'm not upset, I'd like you to allow them (to make) more.'"
The rare communications mean a lot to distraught families desperate for news and struggling to survive with their sole breadwinner in captivity, he says.
"If you see their families," says al-Nauimi, shaking his head, "they are a disaster."
The US has been equally secretive about the detainees' nationalities for diplomatic considerations.
Al-Nauimi confirms recent reports that almost a quarter of the inmates are from Saudi Arabia and, including those of Yemeni origin, number at least 150 – more than the 127 that officials in Riyadh have admitted.
President George Bush labels the
detainees 'enemy combatants'
The suspected role of Saudi nationals in the 9/11 attacks and groups such as al-Qaida, plus Riyadh's links to the Bush administration, has led to heavy criticism of the kingdom in the US media.
The next most represented nationality is Yemeni. Camp Delta reportedly holds about 85 inmates from the Arab country, but al-Nauimi says "families there tell me there are more" and the figure of 110 is "perhaps right".
These detainees, along with several hundred other captives, have been controversially classified as "enemy combatants" by the Bush administration – a term not recognised by international law.
They have been held for up to two years at the US naval base in Cuba, in an apparently deliberate attempt to keep them beyond the reach of civilian courts.
Most legal experts agree the prisoners' detention without access to lawyers and the apparent lack of admissable evidence against them would mean any Western court would probably free them.
A member of Amnesty International, al-Nauimi was moved by the plight of the captives being herded into the detention camp at Guantanamo at the beginning of 2002 and decided to act.
"I sent – you won't believe this – 12,000 emails and faxes to lawyers and groups around the world," says al-Nauimi. "I was then approached by some Saudi and Qatari families who told me: 'We have our sons there'."
He also wrote to 421 US senators and Congressional representatives about the Guantanamo issue, as well as the Senate committee on foreign affairs - but with virtually no response.
A letter to President Bush in April 2002 elicted a polite reply, however, and he was put in touch with the Pentagon. From May 2002, he began meeting Pentagon officials in Washington, notably Defence Department General Counsel William Haynes and Deputy General Counsel Paul "Whit" Cobb.
As a result, he has been recognised as general counsel by the Pentagon and he expects to play a role at the upcoming military tribunals. But he has refused any payment from either his clients or the American side.
"I'm doing this on a humanitarian basis – because it's right."