A senior Hamas official in the occupied West Bank died in Israeli custody after being transferred to Ramon prison in southern Israel, the Palestinian Commission of Detainees Affairs said in a statement.
Mustafa Muhammad Abu Ara, 63, had been imprisoned several times since 1990.
Before his latest arrest on 30 October, Abu Ara was suffering from “serious health problems and needed intensive medical follow-up”, the Palestinian governmental body said.
“However, from the moment of his arrest Sheikh Abu Ara, like all prisoners, has faced unprecedented crimes… since the beginning of the war of extermination,” it added, referring to Israel’s war on Gaza and its crackdown on Palestinians.
He was subjected to medical neglect and torture, the commission said.
It added that around 5,000 Palestinians have been detained by Israel since the war began, without any information provided about them.
The death of Abu Ara raises the number of Palestinian prisoners who have died in Israeli custody to more than 55 since the 7 October Hamas-led attack on Israel and the subsequent war on Gaza.
The death toll in Gaza has exceeded 39,000 people, with around 90,400 wounded, according to local health authorities.