The radio station said that Ms Bibas was likely to have been killed while in captivity with her two young sons, four-year-old Ariel and nine-month-old Kfir.
Israel said on Thursday that Ms Bibas was not among the four bodies handed over on Thursday as part of the ceasefire agreement, instead receiving an “anonymous body without identification”.
The failure to hand over the correct body caused outrage in Israel, and prompted Prime Minister Benjamin Netanyahu to vow that Hamas “pays the full price for this cruel and evil violation”.
Follow latest: Israel claims Hamas killed child hostages with their ‘bare hands’
In a short statement on Friday, the Red Cross confirmed it had received human remains and transferred them to Israeli authorities. The statement did not specify whose remains were believed to be in transit.
Dr Salem Attalah, deputy secretary general for the Palestinian Mujahedeen Brigades, also said it handed over Ms Bibas’ remains to the Red Cross.
The militant group is thought to have been holding the mother and her two children.
Hamas previously claimed there was the “possibility of an error or overlap in the bodies” which may have been caused by Israel “targeting and bombing the place where the family was with other Palestinians”.
Basem Naim, a member of the Hamas political bureau, later said “unfortunate mistakes” occurred and also suggested Israeli bombing had mixed the bodies of Israeli hostages and Palestinians.
He added in a statement: “We confirm that it is not in our values or our interest to keep any bodies or not to abide by the covenants and agreements that we sign.”
Ms Bibas was kidnapped with her sons from the Niz Or kibbutz during the group’s terror attack on Israel in October 2023.
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The IDF confirmed the bodies of the two boys were positively identified on Thursday. However, it claimed the children had been murdered by Hamas with “bare hands”.
Hamas however claimed Ms Bibas and her children were all killed in an Israeli airstrike in November 2023, near the start of the war.
It comes ahead of the next round of hostage releases later today – the final one during the first six-week phase of the ceasefire agreement, which came into effect last month.
The hostages due for release are Eliya Cohen, Omer Shem Tov, Tal Shoham, Omer Wenkert, Hisham al Sayed and Avera Mengisto.
According to the Hamas prisoners’ media office, Israel will be releasing 602 Palestinian prisoners and detainees, adding to the hundreds already released.
