The BBC committed a "serious breach" of media regulations by failing to disclose that the narrator of a programme about Gaza was the child of a Hamas representative, as determined by British broadcasting authority Ofcom.
An investigation by Ofcom into Gaza: How to Survive a Warzone has determined that the film was "significantly deceptive".
The BBC's director general had previously apologised, noting there had been "a serious error in relation to accuracy".
The regulator has directed the broadcaster to transmit a prime-time declaration about its findings.
"Since this amounts to a serious breach of our code, we are ordering the corporation to air a statement of our findings against it on the BBC's second channel at 21:00, with a date to be finalised," the statement read.
'Potential to Damage Credibility'
The watchdog's announcement stated: "The inquiry we conducted concluded that the documentary's lack of disclosure that the voice's male guardian occupied a role in the Hamas-administered administration was materially misleading.
"It meant that the viewers did not have essential details which may have been extremely pertinent to their judgment of the narrator and the details he shared.
"Credibility is at the center of the connection between a media organization and its audience, especially for a state-funded media outlet such as the public broadcaster.
"This oversight had the potential to erode the very considerable degrees of confidence that viewers would have put in a documentary produced by the BBC about the conflict in Gaza."
The film was withdrawn from the online platform in last February after the narrator's personal associations were revealed, and in the month of July an corporation's own inquiry concluded it infringed the broadcaster's editorial guidelines on factual correctness.
A corporation official commented: "The regulator's decision is in line with the results of Peter Johnston's review, that there was a serious error in the programme in relation to the corporation's content standards on truthfulness, which reflects clause 2.2 of the regulator's media standards.
"We issued an apology for this and we accept the regulator's ruling in full. We will follow the sanction as soon as the date and wording are determined."
