The public service broadcaster committed a "major breach" of broadcasting rules by omitting to mention that the presenter of a documentary about Gaza was the offspring of a Hamas administrator, according to regulatory body Ofcom.
An inquiry by Ofcom into Gaza: How to Survive a Warzone has determined that the documentary was "significantly deceptive".
The BBC's director general had already issued an apology, stating there had been "a significant failing in relation to accuracy".
The regulator has directed the BBC to transmit a prime-time declaration about its decisions.
"As this represents a serious breach of our rules, we are instructing the BBC to air a announcement of our conclusions against it on BBC2 at 9pm, with a schedule to be finalised," the regulator stated.
'Risk to Undermine Trust'
The watchdog's announcement said: "Our probe determined that the film's omission to reveal that the presenter's male guardian held a post in the Hamas-administered government was significantly deceptive.
"This implied that the audience did not have vital facts which may have been extremely pertinent to their judgment of the voice and the details he provided.
"Confidence is at the core of the connection between a television network and its audience, notably for a national broadcasting corporation such as the British Broadcasting Corporation.
"This oversight had the potential to erode the very considerable levels of credibility that viewers would have placed in a factual film from the broadcaster about the conflict in Gaza."
The programme was removed from the BBC's streaming service in the month of February after the narrator's personal associations emerged, and in July an corporation's own inquiry concluded it breached the organization's editorial guidelines on accuracy.
A representative for the broadcaster said: "The Ofcom ruling is in accordance with the results of Peter Johnston's review, that there was a significant failing in the documentary in relation to the corporation's content standards on accuracy, which aligns with clause 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we accept the regulator's ruling in complete. We will follow the directive as soon as the timing and language are finalised."
