"Based on this memo, we confirmed to the US administration in writing that Sami al-Hajj is an average Sudanese citizen with no extreme religious affiliations, he practices the religion like all other Sudanese citizens, and that in case he is released he will under no circumstances pose any threat to US security."
The cameraman, who has been accused by the US of having links to al-Qaeda, will only be released if Sudan's government guarantees that al-Hajj will stay in Sudan.
Al-Hajj was arrested in Pakistan in December 2001 on the Afghanistan-Pakistan border by Pakistani intelligence and was handed to the US military in January 2002.
"If the negotiations are moving forward, it's basically because the US is now under greater pressure than ever to close Guantanamo"
Cori Crider, human rights group Reprieve
He has been on hunger strike at Guantanamo for the past seven months in protest at his protracted imprisonment.
Cori Crider, from human rights group Reprieve, said on Wednesday that the organisation was hopeful that al-Hajj would be freed very soon.
"This is now the 220th day of Sami's hunger strike, so whatever negotiations are taking place, it's very important they move forward quickly," she said.
"If the negotiations are moving forward, it's basically because the US is now under greater pressure than ever to close Guantanamo."
Crider said that if rumours were true that al-Hajj's travel would be limited by the US as part of a release deal, it would be an "illegitimate" restriction.
"When the British citizens [held at Guantanamo] were released, there was no such requirement, no one was banned from travelling. There is no reason why Sami should be barred from travelling either," she said.
"How could he be prevented from leaving Sudan? His job is in Doha."
Efforts to speed the release of al-Hajj from Guantanamo recently foundered when members of a Sudanese delegation to the camp were not granted US visas.