The public service broadcaster committed a "significant breach" of broadcasting rules by failing to disclose that the presenter of a film about the Gaza situation was the child of a Hamas administrator, as determined by UK media regulator Ofcom.
An inquiry by the broadcasting watchdog into Gaza: How to Survive a Warzone has concluded that the programme was "materially misleading".
The BBC's director general had earlier expressed regret, noting there had been "a major oversight in relation to factual correctness".
The regulator has instructed the BBC to broadcast a evening announcement about its conclusions.
"Since this amounts to a significant violation of our code, we are directing the BBC to broadcast a message of our findings against it on BBC Two at 9pm, with a timing to be finalised," the regulator stated.
'Potential to Damage Trust'
The regulator's statement said: "Our probe found that the film's lack of disclosure that the presenter's parent occupied a post in the Hamas-run government was materially misleading.
"This implied that the public did not have essential details which may have been very significant to their evaluation of the narrator and the details he shared.
"Confidence is at the heart of the connection between a media organization and its public, notably for a public service broadcaster such as the BBC.
"This oversight had the potential to damage the exceptionally strong degrees of credibility that viewers would have placed in a BBC factual programme about the conflict in Gaza."
The documentary was removed from the BBC's streaming service in February after the narrator's family links emerged, and in this past July an internal BBC review concluded it breached the broadcaster's journalistic standards on truthfulness.
A representative for the broadcaster said: "The authority's determination is in accordance with the conclusions of the corporation's inquiry, that there was a significant failing in the programme in relation to the corporation's content standards on accuracy, which corresponds to Rule 2.2 of the regulator's media standards.
"We have apologised for this and we agree with the authority's determination in complete. We will comply with the penalty as soon as the date and wording are finalised."
