"Of the prisoners, we don't know exactly who among them are alive or dead, killed because of strikes or hunger," Bassem Naim, a senior Hamas leader, told AFP from Cairo.

"There are prisoners held by numerous groups in multiple places" across the Palestinian territory, he said, nearly five months into the war on Gaza.

Naim, a former health minister in Gaza, said that "a ceasefire is necessary so that we can carry out (checks) on this issue... regarding the names, numbers and their status whether alive or dead."

The issue of captives is central to the ongoing negotiations in Cairo for a truce in Gaza.

Qatari and Egyptian mediators were engaged in discussions with United States and Hamas envoys for the second day of talks on Monday.

Israel's government has refused to send its delegation to the Cairo talks, stating they had not been given a list of living captives by Hamas, according to Israeli media reports.

Naim, however, said that details on the status of the prisoners "were not mentioned in any documents or proposals circulated during the negotiation process".

Around 250 captives were taken to the Gaza Strip during the 7 October attack, and Israeli officials say 130 captives are still being held there, including 31 presumed dead.

On Friday Hamas said that seven more captives had died because of Israeli military operations in Gaza. AFP could not independently confirm the information.

In December, Israel's military announced that soldiers killed three captives by mistake, believing they posed a threat.

Israel's offensive in Gaza has killed at least 30,534 people, 70% of them women and children, according to the Palestinian ministry of health.

* This story was edited by Ahram Online.