Israel has accused Hamas of breaching the ongoing ceasefire agreement after the Palestinian group handed over partial remains of a hostage previously returned to Israel, instead of the body of another deceased captive as stipulated in their deal.

In a statement on Tuesday, Prime Minister Benjamin Netanyahu’s office said forensic tests confirmed that the remains handed over late Monday belonged to Ofir Tzarfati, a hostage whose body had already been recovered from Gaza nearly two years ago.

The development, Israeli officials said, constituted a “clear violation” of the U.S.-brokered truce, which took effect on October 10. Under the terms of the deal, Hamas was expected to return 28 hostage bodies in exchange for Israel releasing 420 Palestinian remains.

“The latest remains were identified as belonging to the fallen hostage Ofir Tzarfati, who had been returned from the Gaza Strip in a military operation about two years ago,” Netanyahu’s office said, adding that the prime minister would convene security chiefs to discuss Israel’s response.

The Hostages and Missing Families Forum condemned the action, saying Hamas had acted “with contempt,” deceiving mediators and dishonouring the victims.

“The government cannot and must not ignore this severe breach,” the group said.

Far-right ministers also called for a stronger military response. National Security Minister Itamar Ben-Gvir said Hamas was “still standing” and urged Israel to “break its legs once and for all.” Finance Minister Bezalel Smotrich demanded the re-arrest of all militants released as part of the truce.

Hamas spokesperson Hazem Qassem rejected Israel’s claims, insisting the group did not know the exact locations of the remaining bodies, citing widespread destruction caused by Israeli airstrikes. “We are determined to hand over the bodies of the Israeli captives as soon as possible,” he said.

Hamas has so far returned all 20 living hostages under the ceasefire arrangement.

The October 7, 2023 attack by Hamas resulted in 1,221 Israeli deaths—mostly civilians—and 251 hostages taken. Since then, Israel’s military campaign in Gaza has killed at least 68,531 people, according to the Hamas-run health ministry, figures the UN considers credible.

Despite the ceasefire, tensions remain high, with the ministry reporting that 94 Palestinians have been killed by Israeli fire since the truce began.

Tzarfati’s family confirmed on Tuesday that some of his remains had been returned the previous night, marking the third such occurrence since his death. “This is the third time we have been forced to open Ofir’s grave and rebury our son. The circle supposedly closed back in December 2023, but it never truly closes.” the family said.