The public service broadcaster was found to have committed a "major breach" of media regulations by failing to disclose that the voice of a documentary about Gaza was the offspring of a Hamas administrator, as ruled by British broadcasting authority Ofcom.
An probe by the media regulator into Gaza: How to Survive a Warzone has found that the documentary was "materially misleading".
The BBC's director general had already issued an apology, stating there had been "a major oversight in relation to accuracy".
Ofcom has directed the corporation to transmit a evening declaration about its findings.
"Since this amounts to a major infringement of our rules, we are ordering the corporation to broadcast a message of our determinations against it on BBC Two at 9pm, with a timing to be finalised," the regulator stated.
'Possibility to Undermine Confidence'
The watchdog's announcement stated: "Our investigation found that the film's failure to disclose that the narrator's male guardian occupied a position in the Hamas-run authority was materially misleading.
"This implied that the viewers did not have critical information which may have been highly relevant to their judgment of the voice and the content he presented.
"Trust is at the core of the bond between a television network and its viewers, particularly for a public service broadcaster such as the BBC.
"This failing had the potential to undermine the exceptionally strong levels of credibility that the public would have invested in a factual film from the broadcaster about the Gaza conflict."
The film was removed from the BBC's streaming service in last February after the narrator's personal associations emerged, and in this past July an broadcaster's internal assessment concluded it infringed the corporation's editorial guidelines on accuracy.
A BBC spokesperson said: "The regulator's decision is in line with the conclusions of the internal assessment, that there was a significant failing in the documentary in relation to the corporation's content standards on truthfulness, which aligns with regulation 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we comply with the authority's determination in its entirety. We will follow the penalty as soon as the schedule and wording are determined."
