The BBC committed a "significant breach" of media regulations by omitting to mention that the voice of a film about the Gaza conflict was the son of a Hamas representative, as ruled by British broadcasting authority Ofcom.
An probe by the broadcasting watchdog into Gaza: How to Survive a Warzone has concluded that the film was "materially misleading".
The BBC's director general had previously apologised, saying there had been "a serious error in relation to accuracy".
Ofcom has directed the BBC to broadcast a peak-time statement about its conclusions.
"Given this constitutes a serious breach of our rules, we are instructing the broadcaster to broadcast a announcement of our determinations against it on BBC Two at nine o'clock in the evening, with a timing to be determined," the regulator stated.
'Potential to Damage Confidence'
The authority's report said: "Our investigation determined that the documentary's lack of disclosure that the narrator's parent occupied a post in the Hamas-controlled government was significantly deceptive.
"It meant that the audience did not have critical information which may have been very significant to their judgment of the presenter and the content he presented.
"Trust is at the center of the connection between a television network and its viewers, particularly for a public service broadcaster such as the BBC.
"This failing had the possibility to damage the exceptionally strong degrees of credibility that audiences would have put in a factual film from the broadcaster about the Israel-Gaza war."
The programme was withdrawn from iPlayer in February after the presenter's familial connections were revealed, and in this past July an corporation's own inquiry found it infringed the organization's journalistic standards on truthfulness.
A BBC spokesperson said: "The authority's determination is in accordance with the conclusions of the internal assessment, that there was a significant failing in the documentary in relation to the BBC's Editorial Guidelines on accuracy, which aligns with clause 2.2 of Ofcom's Broadcasting Code.
"We expressed regret for this and we accept the authority's determination in full. We will comply with the directive as soon as the timing and language are determined."
