The public service broadcaster was found to have committed a "serious breach" of media regulations by not revealing that the voice of a film about Gaza was the offspring of a Hamas administrator, as ruled by UK media regulator Ofcom.
An inquiry by the broadcasting watchdog into Gaza: How to Survive a Warzone has concluded that the film was "significantly deceptive".
The BBC's director general had earlier expressed regret, stating there had been "a significant failing in relation to truthfulness".
Ofcom has directed the broadcaster to transmit a prime-time declaration about its conclusions.
"Given this constitutes a significant violation of our regulations, we are instructing the broadcaster to transmit a statement of our determinations against it on the BBC's second channel at 21:00, with a date to be determined," the statement read.
'Possibility to Undermine Trust'
The watchdog's statement declared: "The inquiry we conducted found that the documentary's lack of disclosure that the narrator's parent served in a post in the Hamas-controlled government was substantially inaccurate.
"Consequently that the viewers did not have essential details which may have been highly relevant to their assessment of the presenter and the content he presented.
"Trust is at the heart of the bond between a media organization and its viewers, notably for a national broadcasting corporation such as the BBC.
"This failing had the possibility to damage the very considerable amounts of credibility that the public would have placed in a BBC factual programme about the conflict in Gaza."
The documentary was withdrawn from the online platform in last February after the narrator's family links were revealed, and in July an broadcaster's internal assessment found it breached the broadcaster's content policies on accuracy.
A corporation official commented: "The authority's determination is in accordance with the results of Peter Johnston's review, that there was a significant failing in the programme in relation to the corporation's content standards on truthfulness, which corresponds to regulation 2.2 of the regulator's media standards.
"We have apologised for this and we accept the authority's determination in full. We will comply with the directive as soon as the timing and wording are finalised."
