“He is now on artificial ventilation and his lungs and kidneys are in great distress,” it said in a statement.
A spokeswoman for the Israel Prison Service told AFP that Daqqa is currently at Shamir Medical Centre in central Israel.
Daqqa identifies as Palestinian although he holds citizenship from Israel, which would consider him Arab-Israeli.
Palestinians gathered in the West Bank city of Hebron on Thursday for a rally in solidarity with Daqqa and other Palestinians held by Israel.
The Palestinian Prisoners’ Club said it delivered a letter to the International Committee of the Red Cross (ICRC) in Hebron and nearby Bethlehem, calling for the organization to intervene in Daqqa’s case.
An ICRC spokeswoman told AFP it had received the letter and the organization had previously visited Daqqa.
Daqqa, 61, was diagnosed in December with a rare form of blood cancer — myelofibrosis — the Palestinian Prisoners’ Club said.
The organization said he was also diagnosed with leukemia in 2015 and is currently due to be freed in March 2025.
Judicial authorities in Israel did not immediately respond to an AFP request regarding Daqqa’s appeals for early release on medical grounds.