The BBC was found to have committed a "serious breach" of industry standards by omitting to mention that the voice of a programme about Gaza was the child of a Hamas representative, according to UK media regulator Ofcom.
An investigation by the media regulator into Gaza: How to Survive a Warzone has found that the film was "materially misleading".
The head of the BBC had previously apologised, stating there had been "a significant failing in relation to accuracy".
Ofcom has directed the corporation to air a peak-time declaration about its decisions.
"Since this amounts to a significant violation of our regulations, we are directing the corporation to broadcast a announcement of our findings against it on the BBC's second channel at 21:00, with a schedule to be determined," the regulator stated.
'Possibility to Damage Confidence'
The watchdog's report said: "The inquiry we conducted determined that the documentary's lack of disclosure that the narrator's male guardian occupied a post in the Hamas-administered government was substantially inaccurate.
"This implied that the public did not have critical information which may have been very significant to their judgment of the voice and the information he provided.
"Credibility is at the center of the connection between a television network and its audience, particularly for a public service broadcaster such as the BBC.
"This failing had the possibility to erode the significantly high levels of confidence that audiences would have placed in a factual film from the broadcaster about the conflict in Gaza."
The programme was withdrawn from iPlayer in last February after the narrator's familial connections emerged, and in the month of July an internal BBC review concluded it infringed the organization's journalistic standards on factual correctness.
A corporation official said: "The authority's determination is in accordance with the findings of the corporation's inquiry, that there was a significant failing in the film in relation to the BBC's Editorial Guidelines on accuracy, which aligns with regulation 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we agree with the regulator's ruling in complete. We will follow the penalty as soon as the date and language are confirmed."
