The BBC committed a "major breach" of broadcasting rules by failing to disclose that the presenter of a film about Gaza was the son of a Hamas official, as ruled by British broadcasting authority Ofcom.
An inquiry by Ofcom into Gaza: How to Survive a Warzone has determined that the film was "substantially inaccurate".
The head of the BBC had already issued an apology, stating there had been "a significant failing in relation to truthfulness".
The authority has instructed the broadcaster to broadcast a evening statement about its conclusions.
"Since this amounts to a significant violation of our regulations, we are ordering the corporation to air a statement of our findings against it on the BBC's second channel at nine o'clock in the evening, with a schedule to be confirmed," it said.
'Potential to Damage Confidence'
The authority's announcement stated: "Our probe found that the documentary's failure to disclose that the presenter's male guardian occupied a post in the Hamas-controlled government was materially misleading.
"This implied that the viewers did not have essential details which may have been very significant to their assessment of the voice and the information he provided.
"Credibility is at the heart of the relationship between a media organization and its audience, especially for a public service broadcaster such as the public broadcaster.
"This failing had the potential to undermine the exceptionally strong levels of trust that viewers would have put in a factual film from the broadcaster about the Israel-Gaza war."
The programme was pulled from the online platform in February after the boy's family links were revealed, and in the month of July an internal BBC review concluded it infringed the broadcaster's content policies on truthfulness.
A corporation official said: "The Ofcom ruling is in agreement with the results of Peter Johnston's review, that there was a major oversight in the film in relation to the broadcaster's journalistic policies on factual correctness, which corresponds to clause 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we accept the regulator's ruling in complete. We will follow the penalty as soon as the timing and wording are determined."
