The public service broadcaster engaged in a "major breach" of broadcasting rules by failing to disclose that the voice of a programme about the Gaza situation was the son of a Hamas administrator, as ruled by British broadcasting authority Ofcom.
An inquiry by the broadcasting watchdog into the documentary titled Gaza: How to Survive a Warzone has concluded that the film was "significantly deceptive".
The BBC's director general had previously apologised, stating there had been "a serious error in relation to factual correctness".
The authority has directed the corporation to air a evening declaration about its conclusions.
"Since this amounts to a significant violation of our rules, we are instructing the corporation to broadcast a message of our findings against it on BBC2 at 21:00, with a schedule to be finalised," it said.
'Potential to Erode Credibility'
The regulator's report said: "Our probe determined that the documentary's omission to reveal that the presenter's male guardian occupied a post in the Hamas-run authority was significantly deceptive.
"This implied that the public did not have critical information which may have been highly relevant to their assessment of the presenter and the content he provided.
"Credibility is at the center of the connection between a television network and its audience, especially for a public service broadcaster such as the BBC.
"This error had the risk to erode the significantly high levels of confidence that audiences would have invested in a BBC factual programme about the conflict in Gaza."
The documentary was withdrawn from the online platform in February after the narrator's personal associations came to light, and in July an internal BBC review determined it infringed the corporation's content policies on truthfulness.
A BBC spokesperson stated: "The Ofcom ruling is in agreement with the findings of the internal assessment, that there was a significant failing in the film in relation to the BBC's Editorial Guidelines on accuracy, which aligns with Rule 2.2 of the regulator's media standards.
"We issued an apology for this and we comply with the authority's determination in its entirety. We will comply with the directive as soon as the date and language are determined."
