The British broadcaster committed a "major breach" of broadcasting rules by failing to disclose that the voice of a programme about the Gaza situation was the child of a Hamas administrator, according to regulatory body Ofcom.
An inquiry by the broadcasting watchdog into Gaza: How to Survive a Warzone has determined that the film was "materially misleading".
The head of the BBC had earlier expressed regret, saying there had been "a significant failing in relation to truthfulness".
The regulator has directed the BBC to air a peak-time statement about its findings.
"Given this constitutes a significant violation of our regulations, we are instructing the corporation to broadcast a announcement of our conclusions against it on the BBC's second channel at 21:00, with a schedule to be determined," it said.
'Potential to Undermine Confidence'
The authority's announcement declared: "Our probe concluded that the documentary's omission to reveal that the voice's father occupied a post in the Hamas-administered administration was materially misleading.
"This implied that the audience did not have vital facts which may have been very significant to their assessment of the narrator and the content he presented.
"Confidence is at the core of the connection between a television network and its audience, especially for a national broadcasting corporation such as the public broadcaster.
"This oversight had the risk to damage the exceptionally strong levels of credibility that viewers would have put in a BBC factual programme about the Israel-Gaza war."
The documentary was removed from the online platform in last February after the narrator's family links came to light, and in this past July an internal BBC review found it breached the organization's journalistic standards on accuracy.
A representative for the broadcaster said: "The authority's determination is in agreement with the conclusions of Peter Johnston's review, that there was a significant failing in the documentary in relation to the corporation's content standards on truthfulness, which aligns with clause 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we accept Ofcom's decision in complete. We will adhere to the sanction as soon as the timing and wording are finalised."
