The public service broadcaster was found to have committed a "significant breach" of media regulations by not revealing that the presenter of a programme about the Gaza situation was the son of a Hamas representative, according to British broadcasting authority Ofcom.
An investigation by the broadcasting watchdog into Gaza: How to Survive a Warzone has concluded that the programme was "significantly deceptive".
The BBC's director general had already issued an apology, stating there had been "a significant failing in relation to factual correctness".
The authority has instructed the broadcaster to air a peak-time declaration about its conclusions.
"Given this constitutes a major infringement of our code, we are instructing the corporation to transmit a announcement of our determinations against it on BBC2 at 21:00, with a timing to be determined," the statement read.
'Potential to Erode Credibility'
The watchdog's statement stated: "The inquiry we conducted concluded that the film's lack of disclosure that the narrator's parent served in a post in the Hamas-controlled authority was substantially inaccurate.
"This implied that the public did not have critical information which may have been extremely pertinent to their judgment of the voice and the details he presented.
"Credibility is at the heart of the relationship between a media organization and its audience, especially for a state-funded media outlet such as the BBC.
"This error had the risk to erode the significantly high degrees of credibility that audiences would have placed in a documentary produced by the BBC about the Israel-Gaza war."
The programme was removed from iPlayer in last February after the narrator's personal associations were revealed, and in July an internal BBC review determined it violated the organization's journalistic standards on truthfulness.
A BBC spokesperson commented: "The regulator's decision is in line with the results of Peter Johnston's review, that there was a major oversight in the film in relation to the broadcaster's journalistic policies on accuracy, which reflects regulation 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we comply with the regulator's ruling in complete. We will follow the directive as soon as the timing and wording are determined."
