The public service broadcaster engaged in a "major breach" of broadcasting rules by not revealing that the presenter of a film about the Gaza situation was the son of a Hamas official, as ruled by regulatory body Ofcom.
An inquiry by the media regulator into the documentary titled Gaza: How to Survive a Warzone has determined that the programme was "significantly deceptive".
The BBC's director general had already issued an apology, noting there had been "a major oversight in relation to factual correctness".
The regulator has instructed the BBC to transmit a peak-time announcement about its findings.
"As this represents a significant violation of our code, we are instructing the BBC to transmit a statement of our determinations against it on BBC2 at nine o'clock in the evening, with a schedule to be confirmed," the regulator stated.
'Potential to Erode Trust'
The watchdog's announcement said: "Our probe found that the film's lack of disclosure that the narrator's parent served in a role in the Hamas-run administration was materially misleading.
"This implied that the public did not have essential details which may have been extremely pertinent to their judgment of the narrator and the information he shared.
"Credibility is at the heart of the connection between a media organization and its viewers, particularly for a state-funded media outlet such as the British Broadcasting Corporation.
"This failing had the risk to erode the very considerable levels of confidence that viewers would have placed in a documentary produced by the BBC about the Israel-Gaza war."
The documentary was withdrawn from the BBC's streaming service in last February after the presenter's family links were revealed, and in this past July an internal BBC review found it breached the corporation's content policies on accuracy.
A corporation official stated: "The authority's determination is in line with the results of the corporation's inquiry, that there was a serious error in the film in relation to the BBC's Editorial Guidelines on truthfulness, which corresponds to Rule 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we agree with Ofcom's decision in its entirety. We will adhere to the sanction as soon as the timing and wording are confirmed."
