The BBC committed a "major breach" of media regulations by failing to disclose that the narrator of a documentary about the Gaza situation was the child of a Hamas representative, as determined by British broadcasting authority Ofcom.
An inquiry by the media regulator into Gaza: How to Survive a Warzone has concluded that the film was "substantially inaccurate".
The chief executive of the broadcaster had already issued an apology, stating there had been "a major oversight in relation to truthfulness".
Ofcom has ordered the BBC to air a peak-time announcement about its decisions.
"Since this amounts to a major infringement of our rules, we are directing the corporation to transmit a message of our conclusions against it on the BBC's second channel at 9pm, with a date to be finalised," the statement read.
'Possibility to Damage Trust'
The authority's report declared: "The inquiry we conducted found that the programme's lack of disclosure that the voice's male guardian held a role in the Hamas-administered authority was materially misleading.
"It meant that the audience did not have essential details which may have been very significant to their evaluation of the voice and the details he shared.
"Credibility is at the center of the connection between a television network and its public, notably for a public service broadcaster such as the BBC.
"This oversight had the risk to erode the exceptionally strong degrees of credibility that audiences would have put in a BBC factual programme about the Gaza conflict."
The documentary was removed from the BBC's streaming service in last February after the narrator's personal associations were revealed, and in this past July an internal BBC review determined it infringed the organization's journalistic standards on accuracy.
A representative for the broadcaster said: "The authority's determination is in line with the results of Peter Johnston's review, that there was a significant failing in the film in relation to the broadcaster's journalistic policies on accuracy, which aligns with Rule 2.2 of Ofcom's Broadcasting Code.
"We expressed regret for this and we agree with the authority's determination in full. We will follow the sanction as soon as the date and language are finalised."
