The public service broadcaster engaged in a "major breach" of broadcasting rules by failing to disclose that the voice of a programme about Gaza was the child of a Hamas administrator, as ruled by British broadcasting authority Ofcom.
An investigation by Ofcom into Gaza: How to Survive a Warzone has concluded that the film was "substantially inaccurate".
The chief executive of the broadcaster had previously apologised, saying there had been "a significant failing in relation to truthfulness".
Ofcom has ordered the corporation to air a evening statement about its findings.
"Given this constitutes a major infringement of our code, we are instructing the broadcaster to transmit a message of our conclusions against it on BBC Two at 21:00, with a date to be determined," the statement read.
'Risk to Damage Trust'
The watchdog's announcement stated: "Our probe determined that the documentary's lack of disclosure that the voice's male guardian occupied a position in the Hamas-run authority was substantially inaccurate.
"Consequently that the public did not have essential details which may have been highly relevant to their judgment of the voice and the information he presented.
"Trust is at the heart of the bond between a media organization and its public, especially for a national broadcasting corporation such as the British Broadcasting Corporation.
"This error had the risk to undermine the exceptionally strong levels of confidence that audiences would have put in a BBC factual programme about the Gaza conflict."
The documentary was pulled from the BBC's streaming service in last February after the narrator's personal associations emerged, and in this past July an corporation's own inquiry found it breached the corporation's content policies on factual correctness.
A representative for the broadcaster said: "The authority's determination is in accordance with the results of Peter Johnston's review, that there was a major oversight in the documentary in relation to the broadcaster's journalistic policies on factual correctness, which reflects Rule 2.2 of the regulator's media standards.
"We issued an apology for this and we accept the regulator's ruling in its entirety. We will follow the penalty as soon as the date and wording are confirmed."
