The British broadcaster engaged in a "major breach" of media regulations by not revealing that the narrator of a programme about the Gaza conflict was the offspring of a Hamas administrator, as determined by regulatory body Ofcom.
An probe by the media regulator into Gaza: How to Survive a Warzone has concluded that the film was "materially misleading".
The chief executive of the broadcaster had previously apologised, stating there had been "a significant failing in relation to truthfulness".
The authority has ordered the BBC to transmit a prime-time statement about its findings.
"Since this amounts to a serious breach of our rules, we are instructing the corporation to transmit a message of our determinations against it on BBC Two at nine o'clock in the evening, with a date to be finalised," it said.
'Potential to Erode Credibility'
The watchdog's report declared: "Our investigation concluded that the documentary's failure to disclose that the narrator's parent served in a position in the Hamas-controlled administration was substantially inaccurate.
"Consequently that the viewers did not have essential details which may have been highly relevant to their judgment of the voice and the information he provided.
"Confidence is at the core of the bond between a media organization and its viewers, notably for a public service broadcaster such as the British Broadcasting Corporation.
"This failing had the possibility to undermine the exceptionally strong degrees of trust that the public would have invested in a BBC factual programme about the Israel-Gaza war."
The documentary was withdrawn from iPlayer in last February after the presenter's family links came to light, and in July an internal BBC review determined it infringed the organization's journalistic standards on factual correctness.
A BBC spokesperson stated: "The authority's determination is in accordance with the conclusions of the corporation's inquiry, that there was a major oversight in the film in relation to the corporation's content standards on accuracy, which aligns with clause 2.2 of the regulator's media standards.
"We issued an apology for this and we agree with the regulator's ruling in its entirety. We will comply with the penalty as soon as the date and wording are finalised."
