The public service broadcaster committed a "major breach" of broadcasting rules by failing to disclose that the presenter of a programme about the Gaza situation was the child of a Hamas administrator, according to regulatory body Ofcom.
An inquiry by Ofcom into the programme Gaza: How to Survive a Warzone has determined that the documentary was "significantly deceptive".
The BBC's director general had earlier expressed regret, noting there had been "a major oversight in relation to factual correctness".
The regulator has directed the BBC to broadcast a peak-time declaration about its decisions.
"Given this constitutes a serious breach of our rules, we are instructing the broadcaster to broadcast a message of our findings against it on BBC2 at 21:00, with a schedule to be confirmed," it said.
'Potential to Damage Credibility'
The regulator's statement stated: "Our probe found that the film's lack of disclosure that the voice's parent occupied a position in the Hamas-administered authority was substantially inaccurate.
"It meant that the audience did not have vital facts which may have been highly relevant to their assessment of the narrator and the information he shared.
"Confidence is at the heart of the relationship between a television network and its audience, particularly for a public service broadcaster such as the public broadcaster.
"This error had the potential to erode the very considerable degrees of confidence that audiences would have placed in a documentary produced by the BBC about the Israel-Gaza war."
The film was pulled from the online platform in the month of February after the narrator's familial connections emerged, and in July an corporation's own inquiry found it infringed the broadcaster's editorial guidelines on accuracy.
A BBC spokesperson said: "The Ofcom ruling is in accordance with the findings of the internal assessment, that there was a serious error in the documentary in relation to the BBC's Editorial Guidelines on factual correctness, which corresponds to regulation 2.2 of the regulator's media standards.
"We issued an apology for this and we comply with the authority's determination in its entirety. We will follow the directive as soon as the timing and wording are confirmed."
