The public service broadcaster engaged in a "serious breach" of media regulations by omitting to mention that the narrator of a film about Gaza was the child of a Hamas representative, as determined by regulatory body Ofcom.
An investigation by Ofcom into Gaza: How to Survive a Warzone has found that the programme was "significantly deceptive".
The head of the BBC had previously apologised, noting there had been "a major oversight in relation to truthfulness".
The authority has ordered the BBC to broadcast a prime-time announcement about its conclusions.
"Since this amounts to a major infringement of our rules, we are ordering the corporation to air a statement of our determinations against it on BBC2 at 9pm, with a date to be confirmed," the statement read.
'Risk to Erode Trust'
The regulator's announcement declared: "Our probe found that the film's lack of disclosure that the presenter's parent served in a post in the Hamas-administered government was significantly deceptive.
"This implied that the public did not have vital facts which may have been extremely pertinent to their judgment of the voice and the details he presented.
"Credibility is at the heart of the relationship between a television network and its public, particularly for a national broadcasting corporation such as the public broadcaster.
"This error had the risk to erode the significantly high levels of confidence that audiences would have put in a BBC factual programme about the Israel-Gaza war."
The documentary was withdrawn from the BBC's streaming service in last February after the presenter's familial connections came to light, and in July an corporation's own inquiry determined it breached the broadcaster's journalistic standards on factual correctness.
A corporation official commented: "The Ofcom ruling is in agreement with the conclusions of the internal assessment, that there was a major oversight in the programme in relation to the broadcaster's journalistic policies on truthfulness, which corresponds to clause 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we comply with the regulator's ruling in complete. We will follow the sanction as soon as the date and wording are confirmed."
