The public service broadcaster committed a "serious breach" of media regulations by failing to disclose that the voice of a film about Gaza was the child of a Hamas official, according to regulatory body Ofcom.
An probe by the broadcasting watchdog into the programme Gaza: How to Survive a Warzone has determined that the programme was "materially misleading".
The chief executive of the broadcaster had already issued an apology, stating there had been "a major oversight in relation to accuracy".
Ofcom has directed the corporation to air a peak-time declaration about its decisions.
"Given this constitutes a major infringement of our rules, we are directing the corporation to air a announcement of our findings against it on the BBC's second channel at 9pm, with a schedule to be determined," it said.
'Risk to Erode Credibility'
The regulator's announcement declared: "Our probe concluded that the programme's omission to reveal that the voice's father held a post in the Hamas-administered government was significantly deceptive.
"Consequently that the audience did not have vital facts which may have been extremely pertinent to their evaluation of the presenter and the information he shared.
"Confidence is at the core of the connection between a media organization and its public, particularly for a national broadcasting corporation such as the public broadcaster.
"This failing had the possibility to erode the exceptionally strong levels of credibility that viewers would have put in a BBC factual programme about the Israel-Gaza war."
The documentary was removed from the BBC's streaming service in last February after the narrator's familial connections were revealed, and in the month of July an broadcaster's internal assessment concluded it breached the broadcaster's editorial guidelines on factual correctness.
A representative for the broadcaster said: "The authority's determination is in agreement with the findings of Peter Johnston's review, that there was a significant failing in the film in relation to the broadcaster's journalistic policies on accuracy, which reflects regulation 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we accept the regulator's ruling in its entirety. We will follow the penalty as soon as the timing and wording are finalised."
