The BBC engaged in a "major breach" of industry standards by failing to disclose that the narrator of a film about the Gaza situation was the son of a Hamas administrator, as ruled by British broadcasting authority Ofcom.
An inquiry by Ofcom into Gaza: How to Survive a Warzone has found that the film was "materially misleading".
The BBC's director general had earlier expressed regret, noting there had been "a significant failing in relation to factual correctness".
Ofcom has directed the BBC to transmit a prime-time declaration about its conclusions.
"As this represents a major infringement of our code, we are directing the corporation to broadcast a statement of our conclusions against it on BBC Two at nine o'clock in the evening, with a date to be confirmed," the regulator stated.
'Possibility to Undermine Credibility'
The watchdog's report declared: "The inquiry we conducted found that the programme's omission to reveal that the presenter's male guardian occupied a post in the Hamas-run administration was significantly deceptive.
"It meant that the public did not have critical information which may have been extremely pertinent to their judgment of the voice and the details he shared.
"Confidence is at the center of the bond between a media organization and its audience, especially for a national broadcasting corporation such as the British Broadcasting Corporation.
"This error had the possibility to undermine the very considerable degrees of credibility that the public would have invested in a factual film from the broadcaster about the conflict in Gaza."
The programme was pulled from the BBC's streaming service in last February after the narrator's familial connections came to light, and in this past July an broadcaster's internal assessment concluded it infringed the organization's content policies on accuracy.
A corporation official stated: "The authority's determination is in agreement with the conclusions of Peter Johnston's review, that there was a major oversight in the programme in relation to the corporation's content standards on truthfulness, which reflects regulation 2.2 of Ofcom's Broadcasting Code.
"We expressed regret for this and we comply with Ofcom's decision in complete. We will comply with the sanction as soon as the date and wording are confirmed."
