The BBC committed a "significant breach" of industry standards by failing to disclose that the narrator of a programme about Gaza was the son of a Hamas representative, as determined by UK media regulator Ofcom.
An investigation by the media regulator into Gaza: How to Survive a Warzone has found that the film was "substantially inaccurate".
The chief executive of the broadcaster had already issued an apology, noting there had been "a significant failing in relation to accuracy".
The regulator has ordered the broadcaster to broadcast a peak-time announcement about its findings.
"As this represents a major infringement of our rules, we are directing the broadcaster to broadcast a announcement of our conclusions against it on BBC Two at nine o'clock in the evening, with a timing to be determined," the regulator stated.
'Possibility to Erode Trust'
The watchdog's statement declared: "Our probe concluded that the documentary's failure to disclose that the narrator's father occupied a position in the Hamas-controlled government was significantly deceptive.
"This implied that the viewers did not have critical information which may have been extremely pertinent to their judgment of the narrator and the content he presented.
"Credibility is at the heart of the bond between a broadcaster and its viewers, particularly for a national broadcasting corporation such as the public broadcaster.
"This oversight had the potential to damage the very considerable amounts of trust that viewers would have invested in a BBC factual programme about the conflict in Gaza."
The documentary was withdrawn from the BBC's streaming service in last February after the boy's familial connections emerged, and in the month of July an corporation's own inquiry concluded it breached the corporation's editorial guidelines on accuracy.
A corporation official said: "The authority's determination is in accordance 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 accuracy, which aligns with regulation 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we accept the authority's determination in complete. We will adhere to the sanction as soon as the date and wording are finalised."
