The Israeli prime minister's office did not name the deceased former hostage, saying the remains would be handed over to the National Centre of Forensic Medicine for identification.
Palestinian Islamic Jihad said it found the remains earlier this week in Nuseirat, a refugee camp in the centre of the enclave.
Under the October deal between Hamas and Israel after two years of devastating war, Hamas freed all 20 surviving hostages held in the Gaza Strip in exchange for nearly 2000 Palestinian prisoners and wartime detainees held by Israel.
The pact also stipulated the return of the remains of 28 hostages in exchange for the remains of 360 Palestinian militants.
Meanwhile, Egyptian state-affiliated al-Qahera News TV said on Tuesday that the Cairo government had hosted a follow-up meeting for mediators and guarantors of the ceasefire deal.
It was attended by Egypt's head of intelligence, the Qatari prime minister and the head of Turkish intelligence, the channel said, without mentioning when the gathering was held.
They discussed joint efforts to implement the second phase of US President Donald Trump's 20-point plan for the post-war Gaza Strip and overcome challenges including ceasefire violations to ensure its consolidation, al-Qahera reported.
A Hamas delegation, led by its exiled chief Khalil al-Hayya, held talks with Egyptian officials in Cairo over the past two days to explore how to carry out the next steps in Trump's plan, which would include a transitional governing authority for the enclave and an international security force.
Since the ceasefire took effect on October 10, Israel and Hamas have traded blame for deadly truce violations and accused each other of pushing back against later steps required by the US plan.
Israel's army said on Tuesday that its soldiers had "eliminated" five armed Palestinians in the south of the Gaza Strip.
The incident took place in the east of the city of Rafah, according to an Israel Defence Forces statement.
"IDF troops are continuing to operate in the area of eastern Rafah. Earlier today, during the troops' searches in the area, five armed terrorists were identified and eliminated," it said.
"They were likely the terrorists who emerged from the underground terror infrastructure in eastern Rafah," the statement added.
"IDF troops in the Southern Command remain deployed in accordance with the ceasefire agreement and will continue to operate to remove any immediate threat."
with DPA and AP
