The BBC was found to have committed a "significant breach" of industry standards by omitting to mention that the narrator of a film about the Gaza conflict was the child of a Hamas representative, according to regulatory body Ofcom.
An probe by Ofcom into Gaza: How to Survive a Warzone has determined that the programme was "materially misleading".
The BBC's director general had already issued an apology, saying there had been "a serious error in relation to truthfulness".
Ofcom has instructed the broadcaster to transmit a evening statement about its conclusions.
"As this represents a serious breach of our rules, we are instructing the broadcaster to broadcast a message of our findings against it on BBC Two at nine o'clock in the evening, with a schedule to be confirmed," the regulator stated.
'Possibility to Damage Trust'
The authority's announcement stated: "Our investigation found that the documentary's omission to reveal that the voice's parent held a position in the Hamas-run government was materially misleading.
"Consequently that the public did not have vital facts which may have been extremely pertinent to their assessment of the narrator and the details he presented.
"Credibility is at the center of the bond between a media organization and its audience, particularly for a public service broadcaster such as the public broadcaster.
"This error had the potential to damage the very considerable levels of credibility that audiences would have placed in a documentary produced by the BBC about the conflict in Gaza."
The film was withdrawn from the online platform in last February after the presenter's family links were revealed, and in this past July an corporation's own inquiry determined it violated the corporation's editorial guidelines on factual correctness.
A BBC spokesperson commented: "The regulator's decision 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 corresponds to Rule 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we agree with the regulator's ruling in complete. We will adhere to the sanction as soon as the timing and wording are finalised."
