The BBC engaged in a "significant breach" of industry standards by failing to disclose that the narrator of a film about the Gaza situation was the son of a Hamas representative, according to regulatory body Ofcom.
An inquiry by Ofcom into Gaza: How to Survive a Warzone has found that the programme was "materially misleading".
The chief executive of the broadcaster had already issued an apology, noting there had been "a serious error in relation to truthfulness".
The authority has ordered the corporation to broadcast a prime-time announcement about its conclusions.
"Since this amounts to a serious breach of our code, we are instructing the corporation to air a message of our findings against it on the BBC's second channel at nine o'clock in the evening, with a timing to be confirmed," it said.
'Risk to Undermine Credibility'
The regulator's announcement said: "Our investigation concluded that the programme's failure to disclose that the narrator's parent occupied a role in the Hamas-run government was significantly deceptive.
"Consequently that the public did not have vital facts which may have been extremely pertinent to their assessment of the narrator and the content he provided.
"Credibility is at the heart of the connection between a media organization and its public, especially for a national broadcasting corporation such as the British Broadcasting Corporation.
"This failing had the possibility to undermine the very considerable levels of credibility that audiences would have placed in a BBC factual programme about the Israel-Gaza war."
The film was pulled from the online platform in the month of February after the boy's personal associations emerged, and in this past July an corporation's own inquiry determined it breached the corporation's content policies on accuracy.
A corporation official commented: "The Ofcom ruling is in accordance with the findings of Peter Johnston's review, that there was a serious error in the film in relation to the broadcaster's journalistic policies on truthfulness, which corresponds to clause 2.2 of the authority's broadcasting regulations.
"We have apologised for this and we comply with the regulator's ruling in full. We will comply with the penalty as soon as the date and wording are confirmed."
