The BBC committed a "major breach" of broadcasting rules by not revealing that the narrator of a programme about the Gaza situation was the offspring of a Hamas representative, as ruled by UK media regulator Ofcom.
An investigation by the media regulator into Gaza: How to Survive a Warzone has determined that the programme was "materially misleading".
The chief executive of the broadcaster had previously apologised, saying there had been "a serious error in relation to truthfulness".
Ofcom has instructed the corporation to transmit a peak-time declaration about its decisions.
"Given this constitutes a serious breach of our rules, we are ordering the BBC to broadcast a message of our conclusions against it on BBC2 at 21:00, with a date to be finalised," the regulator stated.
'Risk to Erode Credibility'
The watchdog's announcement stated: "Our investigation found that the film's lack of disclosure that the voice's male guardian served in a role in the Hamas-run administration was significantly deceptive.
"This implied that the public did not have critical information which may have been extremely pertinent to their evaluation of the voice and the content he shared.
"Credibility is at the heart of the connection between a media organization and its audience, particularly for a public service broadcaster such as the BBC.
"This error had the possibility to erode the significantly high degrees of trust that viewers would have invested in a factual film from the broadcaster about the Gaza conflict."
The documentary was withdrawn from iPlayer in the month of February after the presenter's personal associations were revealed, and in July an broadcaster's internal assessment found it violated the broadcaster's journalistic standards on truthfulness.
A corporation official commented: "The authority's determination is in line with the findings of Peter Johnston's review, that there was a major oversight in the documentary in relation to the corporation's content standards on truthfulness, which corresponds to regulation 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we agree with the regulator's ruling in its entirety. We will adhere to the directive as soon as the schedule and wording are determined."
