The British broadcaster was found to have committed a "major breach" of media regulations by omitting to mention that the presenter of a programme about the Gaza conflict was the son of a Hamas administrator, according to UK media regulator Ofcom.
An inquiry by the media regulator into Gaza: How to Survive a Warzone has concluded that the film was "materially misleading".
The BBC's director general had earlier expressed regret, stating there had been "a serious error in relation to factual correctness".
The authority has ordered the broadcaster to transmit a peak-time declaration about its findings.
"Since this amounts to a major infringement of our code, we are instructing the corporation to transmit a message of our determinations against it on the BBC's second channel at 21:00, with a schedule to be finalised," the statement read.
'Potential to Undermine Trust'
The authority's report declared: "Our investigation determined that the documentary's omission to reveal that the presenter's male guardian served in a role in the Hamas-controlled administration was significantly deceptive.
"This implied that the viewers did not have critical information which may have been very significant to their assessment of the voice and the details he shared.
"Trust is at the heart of the connection between a broadcaster and its audience, particularly for a state-funded media outlet such as the British Broadcasting Corporation.
"This oversight had the possibility to erode the exceptionally strong levels of trust that audiences would have invested in a documentary produced by the BBC about the Gaza conflict."
The programme was withdrawn from the BBC's streaming service in February after the narrator's personal associations were revealed, and in this past July an corporation's own inquiry determined it infringed the corporation's editorial guidelines on truthfulness.
A representative for the broadcaster commented: "The authority's determination is in line with the results of Peter Johnston's review, that there was a major oversight in the documentary in relation to the broadcaster's journalistic policies on truthfulness, which corresponds to Rule 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we accept Ofcom's decision in its entirety. We will comply with the sanction as soon as the date and wording are finalised."
