The BBC engaged in a "significant breach" of media regulations by failing to disclose that the presenter of a programme about the Gaza conflict was the offspring of a Hamas official, as determined by UK media regulator Ofcom.
An investigation by the broadcasting watchdog into Gaza: How to Survive a Warzone has concluded that the documentary was "materially misleading".
The head of the BBC had already issued an apology, stating there had been "a major oversight in relation to accuracy".
The authority has instructed the BBC to transmit a peak-time declaration about its findings.
"As this represents a serious breach of our regulations, we are ordering the broadcaster to air a announcement of our conclusions against it on BBC Two at 21:00, with a timing to be confirmed," the regulator stated.
'Possibility to Erode Confidence'
The authority's announcement said: "Our probe found that the documentary's lack of disclosure that the voice's parent occupied a role in the Hamas-run administration was materially misleading.
"This implied that the audience did not have essential details which may have been extremely pertinent to their evaluation of the narrator and the content he presented.
"Confidence is at the core of the relationship between a media organization and its viewers, particularly for a public service broadcaster such as the BBC.
"This oversight had the possibility to damage the exceptionally strong amounts of trust that viewers would have invested in a documentary produced by the BBC about the conflict in Gaza."
The film was pulled from the BBC's streaming service in last February after the narrator's family links were revealed, and in this past July an corporation's own inquiry determined it infringed the corporation's journalistic standards on truthfulness.
A BBC spokesperson stated: "The authority's determination is in line with the findings of the internal assessment, that there was a major oversight in the documentary in relation to the broadcaster's journalistic policies on accuracy, which aligns with Rule 2.2 of Ofcom's Broadcasting Code.
"We expressed regret for this and we accept the authority's determination in its entirety. We will comply with the penalty as soon as the schedule and wording are finalised."
