Three weeks into his protest, al-Hajj has gone from 204 pounds to 168 pounds, according to recently declassified information from a February 1 meeting between al-Hajj and Zachary Katznelson, another lawyer working on the case.
The Commitee to Protect Journalists, an independent group that promotes press freedom, said the US military began feeding al-Hajj through intravenous therapy on January 27 and then on January 29 through a tube inserted through his nose, connecting to his stomach.
Al-Hajj, 38, was born in Khartoum and is a Sudanese national.
Stafford-Smith said: "The case warrants diplomatic efforts with the US but because Khartoum’s relations with Washington are not good, a third party should pitch in and that party could well be Qatar since it is the headquarters of Al Jazeera's network which has showed great concern over the case."
The lawyer said he visits his client every six to eight weeks, but complained that these visits were not enough.
In a related development, the Sudanese government has renewed its call on the US administration to release the Sudanese nationals detained in Guantanamo or present them before court.
Dr Lam Akol, minister of foreign affairs, met Andrew Natsios, the US envoy to Sudan, on Wednesday
Akol said that he had requested a response to the repeated contacts and the messages sent by the Sudanese government to the US administration concerning the release of the detainees.
Road to Guantanamo
Al-Hajj was a member of the Al Jazeera news team that covered the US invasion of Afghanistan in 2001.
He was arrested by Pakistani police in December of that year in Chaman when he and a colleague tried to re-enter Afghanistan. Al Jazeera had asked them to cover the inauguration of the new government.
Al-Hajj was detained because of a Pakistani intelligence notice that called for his arrest because of suspected links to al-Qaeda.
He was held in Pakistan for 23 days and on January 7, 2002, was moved to a military jail in Quetta, that same night he was handed over to US forces.
Having confiscated his passport, airline ticket to Doha and Al Jazeera press card, American troops transferred him to a detention centre at Bagram airbase in Afghanistan.
Al-Hajj describes the 16 days he spent at the base as the worst of his life.
He claims that he was tortured before being transferred to Kandahar in southern Afghanistan for five months, where he says he received similar treatment.
Beaten and abused
On June 13, 2002, al-Hajj was transferred to Guantanamo Bay. On the flight there he claims that prisoners were not allowed to sleep and had to wear gloves, eye goggles, gags and have their hands and feet linked by shackles.
At Guantanamo, al-Hajj said he has been beaten and abused by interrogators, who demanded that he incriminate Al Jazeera.
He said he was asked to spy for the US in exchange for citizenship and that the interrogators threatened to harm his family, including his five-year-old son, if he did not comply.