The public service broadcaster was found to have committed a "significant breach" of media regulations by not revealing that the voice of a programme about Gaza was the son of a Hamas official, as determined by British broadcasting authority Ofcom.
An inquiry by Ofcom into the documentary titled Gaza: How to Survive a Warzone has determined that the programme was "materially misleading".
The BBC's director general had previously apologised, noting there had been "a significant failing in relation to accuracy".
Ofcom has directed the BBC to transmit a peak-time declaration about its findings.
"Given this constitutes a major infringement of our code, we are ordering the broadcaster to broadcast a statement of our determinations against it on BBC2 at nine o'clock in the evening, with a date to be finalised," the statement read.
'Possibility to Erode Credibility'
The authority's announcement said: "Our investigation concluded that the programme's failure to disclose that the voice's parent served in a role in the Hamas-run administration was substantially inaccurate.
"It meant that the audience did not have vital facts which may have been very significant to their evaluation of the presenter and the information he presented.
"Credibility is at the center of the relationship between a television network and its audience, particularly for a state-funded media outlet such as the BBC.
"This failing had the potential to undermine the significantly high levels of confidence that the public would have invested in a documentary produced by the BBC about the Israel-Gaza war."
The film was removed from the BBC's streaming service in February after the narrator's family links were revealed, and in this past July an internal BBC review determined it infringed the organization's editorial guidelines on factual correctness.
A representative for the broadcaster said: "The Ofcom ruling is in agreement with the conclusions of the internal assessment, that there was a serious error in the documentary in relation to the BBC's Editorial Guidelines on accuracy, which aligns with Rule 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we comply with the regulator's ruling in its entirety. We will adhere to the sanction as soon as the date and language are finalised."
