Video footage of Jewish zealots mocking the death by arson of a Palestinian baby has sparked outrage in Israel, even as some on the far right saw in the leak a possible bid to justify tough interrogation of suspects in the killing.

Aired on Israel's Channel 10 television late on Wednesday, the clip showed a wedding at which one dancing celebrant stabbed a picture of 18-month-old Ali Dawabsheh while others waved assault rifles, knives and what appeared to be a petrol bomb.

The boy and his parents died when their home in the village of Duma in the occupied West Bank was set ablaze in July in an incident Israeli officials described as "Jewish terrorism".