The BBC was found to have committed a "significant breach" of media regulations by omitting to mention that the presenter of a documentary about the Gaza conflict was the child of a Hamas official, as ruled by British broadcasting authority Ofcom.
An probe by Ofcom into the programme Gaza: How to Survive a Warzone has concluded that the film was "materially misleading".
The BBC's director general had already issued an apology, stating there had been "a significant failing in relation to accuracy".
The authority has instructed the broadcaster to transmit a peak-time statement about its findings.
"Given this constitutes a serious breach of our regulations, we are directing the broadcaster to broadcast a statement of our findings against it on BBC2 at 21:00, with a date to be determined," it said.
'Risk to Undermine Trust'
The regulator's report said: "Our investigation found that the film's lack of disclosure that the presenter's father held a post in the Hamas-run government was significantly deceptive.
"It meant that the audience did not have critical information which may have been very significant to their judgment of the voice and the content he provided.
"Trust is at the core of the relationship between a television network and its audience, especially for a national broadcasting corporation such as the British Broadcasting Corporation.
"This oversight had the potential to damage the exceptionally strong amounts of trust that the public would have invested in a factual film from the broadcaster about the Israel-Gaza war."
The documentary was pulled from the BBC's streaming service in February after the boy's familial connections came to light, and in July an broadcaster's internal assessment determined it breached the corporation's editorial guidelines on factual correctness.
A BBC spokesperson commented: "The Ofcom ruling is in line with the conclusions of Peter Johnston's review, that there was a serious error in the documentary in relation to the corporation's content standards on accuracy, which corresponds to Rule 2.2 of the regulator's media standards.
"We expressed regret for this and we comply with the regulator's ruling in complete. We will comply with the penalty as soon as the timing and wording are finalised."
