The British broadcaster committed a "significant breach" of media regulations by omitting to mention that the voice of a film about Gaza was the son of a Hamas administrator, as ruled by British broadcasting authority Ofcom.
An inquiry by the broadcasting watchdog into Gaza: How to Survive a Warzone has determined that the documentary was "substantially inaccurate".
The BBC's director general had earlier expressed regret, stating there had been "a significant failing in relation to accuracy".
Ofcom has instructed the BBC to broadcast a peak-time announcement about its conclusions.
"As this represents a major infringement of our rules, we are instructing the broadcaster to broadcast a message of our determinations against it on BBC Two at nine o'clock in the evening, with a schedule to be finalised," the regulator stated.
'Possibility to Erode Trust'
The regulator's report stated: "Our investigation concluded that the documentary's lack of disclosure that the narrator's father occupied a position in the Hamas-controlled administration was substantially inaccurate.
"Consequently that the audience did not have essential details which may have been very significant to their judgment of the narrator and the details he presented.
"Credibility is at the heart of the connection between a media organization and its viewers, especially for a national broadcasting corporation such as the public broadcaster.
"This failing had the risk to erode the very considerable levels of credibility that audiences would have placed in a BBC factual programme about the conflict in Gaza."
The documentary was pulled from the online platform in last February after the narrator's familial connections emerged, and in the month of July an corporation's own inquiry determined it infringed the corporation's journalistic standards on accuracy.
A representative for the broadcaster stated: "The Ofcom ruling is in agreement with the results of the corporation's inquiry, that there was a significant failing in the film in relation to the broadcaster's journalistic policies on factual correctness, which reflects regulation 2.2 of the regulator's media standards.
"We expressed regret for this and we accept Ofcom's decision in its entirety. We will comply with the penalty as soon as the date and language are finalised."
