The BBC committed a "major breach" of media regulations by not revealing that the voice of a programme about the Gaza situation was the offspring of a Hamas official, according to UK media regulator Ofcom.
An probe by Ofcom into the programme Gaza: How to Survive a Warzone has determined that the film was "substantially inaccurate".
The head of the BBC had previously apologised, saying there had been "a serious error in relation to truthfulness".
The authority has instructed the corporation to air a prime-time announcement about its decisions.
"As this represents a serious breach of our code, we are ordering the BBC to transmit a statement of our findings against it on the BBC's second channel at 9pm, with a schedule to be determined," the regulator stated.
'Risk to Erode Credibility'
The watchdog's statement declared: "The inquiry we conducted determined that the programme's failure to disclose that the narrator's male guardian served in a post in the Hamas-controlled authority was significantly deceptive.
"It meant that the audience did not have essential details which may have been highly relevant to their judgment of the presenter and the details he shared.
"Confidence is at the center of the connection between a broadcaster and its audience, notably for a state-funded media outlet such as the British Broadcasting Corporation.
"This oversight had the risk to erode the exceptionally strong degrees of confidence that viewers would have invested in a factual film from the broadcaster about the conflict in Gaza."
The documentary was pulled from the online platform in February after the presenter's family links were revealed, and in this past July an corporation's own inquiry found it breached the corporation's journalistic standards on factual correctness.
A BBC spokesperson stated: "The authority's determination is in line with the conclusions of the internal assessment, that there was a serious error in the film in relation to the corporation's content standards on truthfulness, which aligns with regulation 2.2 of the authority's broadcasting regulations.
"We have apologised for this and we agree with Ofcom's decision in full. We will adhere to the sanction as soon as the timing and wording are finalised."
