The public service broadcaster was found to have committed a "major breach" of broadcasting rules by not revealing that the voice of a programme about Gaza was the son of a Hamas administrator, as determined by British broadcasting authority Ofcom.
An investigation by the media regulator into the documentary titled Gaza: How to Survive a Warzone has concluded that the film was "significantly deceptive".
The head of the BBC had previously apologised, saying there had been "a significant failing in relation to factual correctness".
The regulator has ordered the corporation to air a peak-time declaration about its findings.
"As this represents a significant violation of our code, we are instructing the corporation to air a announcement of our findings against it on BBC2 at nine o'clock in the evening, with a schedule to be confirmed," it said.
'Possibility to Damage Trust'
The watchdog's report stated: "Our probe concluded that the documentary's omission to reveal that the narrator's parent served in a role in the Hamas-run government was significantly deceptive.
"This implied that the public did not have vital facts which may have been very significant to their judgment of the narrator and the details he presented.
"Credibility is at the core of the connection between a television network and its public, especially for a state-funded media outlet such as the BBC.
"This oversight had the possibility to damage the significantly high degrees of confidence that audiences would have put in a factual film from the broadcaster about the Israel-Gaza war."
The film was pulled from the BBC's streaming service in last February after the narrator's familial connections were revealed, and in this past July an internal BBC review found it infringed the organization's journalistic standards on factual correctness.
A representative for the broadcaster said: "The authority's determination is in accordance with the findings of the corporation's inquiry, that there was a significant failing in the programme in relation to the corporation's content standards on truthfulness, which aligns with Rule 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we accept the authority's determination in full. We will comply with the penalty as soon as the date and wording are confirmed."
