The BBC committed a "serious breach" of media regulations by not revealing that the presenter of a film about Gaza was the son of a Hamas representative, according to UK media regulator Ofcom.
An probe by the broadcasting watchdog into the programme Gaza: How to Survive a Warzone has found that the film was "materially misleading".
The head of the BBC had already issued an apology, stating there had been "a significant failing in relation to truthfulness".
Ofcom has instructed the BBC to transmit a evening declaration about its conclusions.
"Since this amounts to a serious breach of our regulations, we are ordering the BBC to broadcast a statement of our findings against it on the BBC's second channel at nine o'clock in the evening, with a timing to be finalised," the regulator stated.
'Risk to Damage Credibility'
The watchdog's announcement declared: "Our probe found that the documentary's lack of disclosure that the narrator's male guardian served in a post in the Hamas-run government was materially misleading.
"It meant that the public did not have vital facts which may have been extremely pertinent to their judgment of the presenter and the details he provided.
"Confidence is at the core of the connection between a broadcaster and its public, particularly for a state-funded media outlet such as the British Broadcasting Corporation.
"This failing had the potential to undermine the very considerable levels of trust that viewers would have placed in a documentary produced by the BBC about the Israel-Gaza war."
The programme was pulled from the BBC's streaming service in the month of February after the boy's familial connections came to light, and in July an corporation's own inquiry determined it infringed the broadcaster's journalistic standards on factual correctness.
A corporation official said: "The regulator's decision is in agreement with the findings of Peter Johnston's review, that there was a significant failing in the programme in relation to the broadcaster's journalistic policies on factual correctness, which corresponds to regulation 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we comply with the regulator's ruling in full. We will comply with the sanction as soon as the timing and wording are finalised."
