The British broadcaster engaged in a "major breach" of industry standards by omitting to mention that the presenter of a documentary about Gaza was the child of a Hamas representative, according to UK media regulator Ofcom.
An investigation by Ofcom into the programme Gaza: How to Survive a Warzone has concluded that the programme was "materially misleading".
The chief executive of the broadcaster had earlier expressed regret, saying there had been "a major oversight in relation to truthfulness".
The regulator has directed the BBC to broadcast a peak-time announcement about its conclusions.
"Since this amounts to a major infringement of our code, we are instructing the BBC to broadcast a announcement of our determinations against it on the BBC's second channel at nine o'clock in the evening, with a schedule to be confirmed," the statement read.
'Risk to Erode Confidence'
The regulator's announcement stated: "The inquiry we conducted determined that the documentary's omission to reveal that the presenter's father held a role in the Hamas-run authority was materially misleading.
"Consequently that the audience did not have critical information which may have been highly relevant to their judgment of the narrator and the information he presented.
"Credibility is at the center of the bond between a broadcaster and its audience, notably for a public service broadcaster such as the British Broadcasting Corporation.
"This failing had the risk to damage the exceptionally strong amounts of trust that viewers would have invested in a factual film from the broadcaster about the conflict in Gaza."
The programme was removed from the BBC's streaming service in February after the narrator's family links emerged, and in July an broadcaster's internal assessment found it infringed the corporation's editorial guidelines on accuracy.
A BBC spokesperson stated: "The Ofcom ruling is in line with the results of Peter Johnston's review, that there was a major oversight in the documentary in relation to the corporation's content standards on truthfulness, which corresponds to regulation 2.2 of the regulator's media standards.
"We expressed regret for this and we comply with the authority's determination in full. We will adhere to the penalty as soon as the timing and wording are determined."
