I don't think it's just a "claim": it's in the BBC report here:
As we reported earlier, the family of Shiri Bibas says that last night she was "brought home".
That came after the remains Hamas handed over in Gaza on Thursday turned out not to be hers.
By Friday night, Hamas handed over another body that Israel has now identified as hers.
The incident caused shock and anger in Israel.
In response, Hamas said there might have been an error, perhaps due - it said - to human remains becoming mixed due to Israeli air strikes.
That raises the question of why they were then able to provide her genuine remains so swiftly. No explanation of that has yet been given.
Israeli military spokesperson Daniel Hagari has dismissed Hamas's claim that Shiri Bibas and her children were killed in an Israeli air strike as lies.
Hamas was not the Palestinian armed faction that abducted Shiri Bibas or her children, nor is it believed to have held them afterwards.
That could suggest that Hamas did not have full command of the process of the handover of her body and perhaps didn't make necessary checks.
The body that was originally handed over is unknown, but it was not that of another hostage, according to Israel.
There is also the possibility that Hamas did it knowingly but that raises questions over why it would wish to endanger the already fragile ceasefire with such a blatantly provocative act.