Family of hunger-striking detainee Mohamed Soltan have said that they are "terrified” by their son's sharply deteriorating condition and have called for his immediate release.   

The family said Soltan, 27, had suffered a number of heart attacks and lost consciousness repeatedly in the course of his hunger strike, as well as losing more than half his body weight.

Soltan, an Egyptian-American, was a media spokesman at the pro-Mohamed Morsi protest camp in Cairo’s Rabaa Al-Adawiya in 2013. He was arrested shortly after the camp’s dispersal in August 2013, and has been in detention since.

He is facing charges along with 50 others in relation to setting up an operations room at the protest camp. His family say he was not a Muslim Brotherhood member and had originally returned to Egypt from the USA to care for his sick mother.

In a statement published publicly on Tuesday on his brother Omar Soltan's Facebook account, the family expressed their "resentment" at the treatment he is receiving in prison and called on rights groups and the US to work on releasing him.

They claim authorities put pressure on him to "weaken his morale" and isolate him from fellow prisoners.

They posted a photo showing Soltan, who has been on hunger strike for about a year, lying in bed with eyes closed and mouth open, with a bloodstain on the pillow near his mouth.

He was admitted to prison hospital several times. He also spent a brief period at Kasr El-Aini Hospital in December. 

A number of other detainees and prisoners are also on hunger strike in Egyptian prisons, in protest at what they describe as unjust charges against them. They include prominent human rights  activist Alaa Abdel-Fattah.