Leading Moroccan Human Rights Association (AMDH) said in a statement on Friday that the health of the hunger strikers, who began their action on 8 August, is deteriorating and one of the 12 was released on parole this week because of fears for his health.
One of them, "Lahsen Zirikinat, was released on Wednesday", AMDH spokesman Abdelilah Benabdeslam said.
Zirikinat was set free on parole after falling unconscious and being rushed to hospital, the group's statement said.
"His family worries about his health after his condition deteriorated seriously and fears that the authorities released him because they do not want to be accountable for his fate," the statement said.
The AMDH named 11 prisoners who it said had fallen into coma or unconsciousness between 22 August and 6 September before being taking to hospital to be resuscitated and returned to jail, where they had resumed their fast. Most of the 35 were detained after anti-Moroccan riots in the territory in May.
Morocco, claiming centuries-old rights over the desert territory, regained Western Sahara after colonial power Spain pulled out in 1975, and is opposed by the Algeria-based Polisario Front, which wants independence for the territory.
Polisario recently asked the United Nations to intervene to avoid deaths among the hunger strikers.
Most of the 35 were detained
after anti-Moroccan riots in May
The prisoners went on hunger strike to back demands for better conditions at the three jails at which they are being held, one in the disputed territory and two in northern Morocco, the AMDH said.
They want to be moved to jails closer to their relatives, and want Rabat to lift what they call its heavy security deployment in Laayoun, the main town in Western Sahara, it said.
The association said it and three other rights groups asked the Justice Ministry last week to let them visit the fasting detainees but the ministry ignored their request.
"The Justice Minister (Mohamed Bouzoubaa) had already stated there was no hunger strike, so they deny us visits to witness first hand the seriousness of the health of the fasting prisoners and avoid a dialogue with the detainees," said Benabdeslam.
"The Justice Minister deny us visits to witness first hand the seriousness of the health of the fasting prisoners"
AMDH spokesman Abdelilah Benabdeslam
Government officials in Rabat were not immediately available for comment but the minister said in a statement earlier this week the prisoners were enjoying "all their rights as detainees including the right to have access to the media and healthcare".
The minister accused the hunger strikers of "raising claims not related to the conditions of their jailing but claims having a political nature that show them as supporters of separatism".