The public service broadcaster committed a "major breach" of media regulations by not revealing that the voice of a film about the Gaza conflict was the offspring of a Hamas administrator, as ruled by British broadcasting authority Ofcom.
An probe by Ofcom into the documentary titled Gaza: How to Survive a Warzone has determined that the film was "substantially inaccurate".
The head of the BBC had already issued an apology, saying there had been "a serious error in relation to truthfulness".
The authority has directed the corporation to air a peak-time declaration about its findings.
"Given this constitutes a serious breach of our code, we are ordering the broadcaster to air a announcement of our determinations against it on BBC2 at 9pm, with a date to be finalised," it said.
'Potential to Damage Trust'
The watchdog's announcement declared: "Our investigation concluded that the programme's failure to disclose that the presenter's male guardian served in a role in the Hamas-administered government was substantially inaccurate.
"This implied that the viewers did not have essential details which may have been extremely pertinent to their assessment of the narrator and the content he shared.
"Confidence is at the center of the connection between a media organization and its audience, especially for a national broadcasting corporation such as the BBC.
"This failing had the potential to undermine the exceptionally strong amounts of credibility that viewers would have placed in a BBC factual programme about the Israel-Gaza war."
The programme was removed from iPlayer in last February after the boy's personal associations emerged, and in this past July an corporation's own inquiry concluded it infringed the corporation's journalistic standards on truthfulness.
A BBC spokesperson said: "The Ofcom ruling is in agreement with the results of the corporation's inquiry, that there was a significant failing in the documentary in relation to the corporation's content standards on factual correctness, which corresponds to regulation 2.2 of the regulator's media standards.
"We issued an apology for this and we accept the regulator's ruling in its entirety. We will follow the sanction as soon as the timing and wording are finalised."
