The BBC engaged in a "significant breach" of media regulations by not revealing that the narrator of a programme about Gaza was the offspring of a Hamas representative, as determined by British broadcasting authority Ofcom.
An investigation by Ofcom into the programme Gaza: How to Survive a Warzone has concluded that the film was "materially misleading".
The chief executive of the broadcaster had earlier expressed regret, stating there had been "a serious error in relation to factual correctness".
The regulator has instructed the corporation to air a evening announcement about its findings.
"Given this constitutes a major infringement of our regulations, we are instructing the corporation to air a message of our conclusions against it on the BBC's second channel at 9pm, with a schedule to be confirmed," it said.
'Possibility to Undermine Confidence'
The regulator's announcement said: "The inquiry we conducted concluded that the film's omission to reveal that the narrator's parent held a role in the Hamas-run government was substantially inaccurate.
"Consequently that the public did not have vital facts which may have been highly relevant to their assessment of the voice and the content he shared.
"Confidence is at the center of the relationship between a media organization and its audience, particularly for a national broadcasting corporation such as the British Broadcasting Corporation.
"This error had the possibility to undermine the significantly high degrees of trust that audiences would have invested in a factual film from the broadcaster about the Israel-Gaza war."
The programme was pulled from iPlayer in the month of February after the narrator's family links came to light, and in July an internal BBC review determined it violated the corporation's journalistic standards on truthfulness.
A representative for the broadcaster commented: "The authority's determination is in line with the findings of the corporation's inquiry, that there was a major oversight in the documentary in relation to the broadcaster's journalistic policies on truthfulness, which corresponds to clause 2.2 of the regulator's media standards.
"We expressed regret for this and we comply with the authority's determination in complete. We will adhere to the penalty as soon as the timing and wording are finalised."
