The public service broadcaster committed a "significant breach" of media regulations by not revealing that the narrator of a programme about Gaza was the son of a Hamas representative, as determined by British broadcasting authority Ofcom.
An investigation by the media regulator into the programme Gaza: How to Survive a Warzone has concluded that the programme was "materially misleading".
The BBC's director general had already issued an apology, stating there had been "a serious error in relation to factual correctness".
The regulator has instructed the BBC to air a prime-time declaration about its conclusions.
"As this represents a major infringement of our code, we are directing the corporation to transmit a announcement of our conclusions against it on the BBC's second channel at nine o'clock in the evening, with a timing to be finalised," it said.
'Risk to Damage Credibility'
The authority's announcement declared: "The inquiry we conducted found that the programme's omission to reveal that the voice's male guardian held a post in the Hamas-run authority was substantially inaccurate.
"It meant that the viewers did not have critical information which may have been extremely pertinent to their judgment of the narrator and the details he provided.
"Trust is at the heart of the relationship between a media organization and its public, notably for a public service broadcaster such as the public broadcaster.
"This oversight had the risk to erode the exceptionally strong degrees of trust that the public would have put in a factual film from the broadcaster about the Israel-Gaza war."
The film was removed from the online platform in February after the presenter's familial connections came to light, and in the month of July an internal BBC review found it breached the corporation's content policies on truthfulness.
A BBC spokesperson said: "The authority's determination is in agreement with the conclusions of the corporation's inquiry, that there was a major oversight in the documentary in relation to the broadcaster's journalistic policies on factual correctness, which aligns with Rule 2.2 of the regulator's media standards.
"We issued an apology for this and we agree with the regulator's ruling in its entirety. We will follow the sanction as soon as the date and wording are finalised."
