The BBC engaged in a "major breach" of industry standards by not revealing that the narrator of a film about Gaza was the offspring of a Hamas representative, as ruled by British broadcasting authority Ofcom.
An inquiry by the broadcasting watchdog into the documentary titled Gaza: How to Survive a Warzone has found that the film was "materially misleading".
The head of the BBC had earlier expressed regret, stating there had been "a major oversight in relation to accuracy".
Ofcom has directed the corporation to broadcast a peak-time announcement about its conclusions.
"Since this amounts to a significant violation of our code, we are ordering the BBC to transmit a statement of our conclusions against it on BBC Two at nine o'clock in the evening, with a schedule to be finalised," the regulator stated.
The watchdog's announcement stated: "Our investigation determined that the film's lack of disclosure that the presenter's father held a post in the Hamas-administered government was significantly deceptive.
"Consequently that the public did not have vital facts which may have been extremely pertinent to their judgment of the presenter and the content he shared.
"Credibility is at the center of the relationship between a television network and its audience, especially for a national broadcasting corporation such as the British Broadcasting Corporation.
"This failing had the possibility to undermine the significantly high levels of credibility that audiences would have placed in a documentary produced by the BBC about the conflict in Gaza."
The documentary was removed from the online platform in last February after the presenter's familial connections were revealed, and in July an internal BBC review determined it infringed the broadcaster's journalistic standards on factual correctness.
A BBC spokesperson said: "The Ofcom ruling is in line with the findings of the internal assessment, that there was a significant failing in the documentary in relation to the BBC's Editorial Guidelines on factual correctness, which corresponds to regulation 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we comply with the authority's determination in complete. We will adhere to the sanction as soon as the timing and language are confirmed."
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