Hamas said it would hand over a hostage body on Wednesday, after Israeli forensic services concluded that remains returned a day earlier were not from one of two final deceased hostages.
The handover of the last two hostages' bodies in Gaza would complete a key condition of the initial part of US President Donald Trump's plan to end the Gaza war.
Hamas said it would hand over the body at 5 pm local time (1300 GMT).
The armed wing of the Hamas-allied IJ movement, The Al Quds Brigades, said it had conducted a search in northern Gaza, along with a team from the Red Cross.
The group later said it found a body, but it did not say which of the two remaining deceased hostages it believed it to be.
The two are Israeli police officer Ran Gvili and Thai national Sudthisak Rinthalak, both kidnapped during Hamas' October 7, 2023 attack on Israel that triggered two years of devastating war in Gaza.
The search came soon after Israel's National Centre for Forensic Medicine concluded that remains handed over by Hamas on Tuesday were not those of the final two hostages in Gaza, the office of Israel's prime minister said.
Israeli forces said they sent the remains they described as "findings" for forensic testing.
"The findings brought yesterday for examination from the Gaza Strip are not linked to any of the deceased hostages," Prime Minister Benjamin Netanyahu's office said in a statement on Wednesday.
Hamas had handed over remains to the Geneva-based Red Cross, which has acted as an intermediary between Gaza groups and Israel throughout the war.

US, Iran reach preliminary agreement to end war, signing set for Friday
Lebanon fighting eases after US-Iran deal but displaced warned not to rush home
Ukrainian man found guilty of setting on fire houses linked to UK PM Starmer
Britain announces sweeping social media ban for under-16s
Historic monastery damaged, 10 people killed in Russian attacks on Ukraine
