The public service broadcaster engaged in a "serious breach" of media regulations by not revealing that the narrator of a programme about Gaza was the child of a Hamas official, as ruled by regulatory body Ofcom.
An inquiry by Ofcom into Gaza: How to Survive a Warzone has concluded that the programme was "significantly deceptive".
The chief executive of the broadcaster had already issued an apology, stating there had been "a significant failing in relation to truthfulness".
The regulator has ordered the broadcaster to transmit a prime-time declaration about its decisions.
"As this represents a significant violation of our regulations, we are instructing the corporation to transmit a statement of our conclusions against it on BBC2 at 9pm, with a date to be confirmed," it said.
'Risk to Undermine Credibility'
The authority's statement stated: "The inquiry we conducted determined that the film's lack of disclosure that the narrator's parent occupied a role in the Hamas-run authority was materially misleading.
"It meant that the audience did not have critical information which may have been very significant to their judgment of the presenter and the content he presented.
"Confidence is at the heart of the bond between a television network and its audience, notably for a state-funded media outlet such as the BBC.
"This oversight had the potential to undermine the exceptionally strong levels of credibility that viewers would have placed in a documentary produced by the BBC about the conflict in Gaza."
The film was pulled from iPlayer in February after the narrator's family links emerged, and in the month of July an broadcaster's internal assessment found it violated the corporation's content policies on factual correctness.
A BBC spokesperson said: "The regulator's decision is in agreement with the results of the internal assessment, that there was a serious error in the film in relation to the broadcaster's journalistic policies on accuracy, which corresponds to regulation 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we accept the regulator's ruling in complete. We will follow the penalty as soon as the schedule and wording are confirmed."
