Under the first phase of the US-brokered ceasefire deal, which took effect on 10 October, Hamas agreed to return the 20 living Israeli hostages and the bodies of the 28 dead Israeli and foreign hostages still in Gaza within 72 hours.
All the living hostages were released on 13 October in exchange for 250 Palestinian prisoners and 1,718 detainees from Gaza.
So far, the remains of 23 dead Israeli hostages have been handed over, along with those of three foreign hostages – one of them Thai, one Nepalese and one Tanzanian.
In exchange, Israel has handed over the bodies of 330 Palestinians killed during the war. It should hand over another 15 bodies in return for Mr Or's remains.
One of the remaining dead hostages is Israeli - Ran Gvili, 24 - and the other is Thai - Suthisak Rintalak, 43.
Israel has accused Hamas of deliberately delaying the recovery of the hostages' bodies, while Hamas has insisted it is struggling to find them under rubble.
The slow progress has meant there has been no advance on the second phase of President Donald Trump's Gaza peace plan. This includes plans for the governance of Gaza, the withdrawal of Israeli troops, the disarmament of Hamas and reconstruction.
The two dead hostages still in Gaza were among the 251 people abducted by Hamas and its allies on 7 October 2023, when about 1,200 other people were killed.
Israel responded to the attack by launching a military campaign in Gaza, during which more than 69,770 people have been killed, according to the territory's Hamas-run health ministry.