The BBC committed a "major breach" of broadcasting rules by not revealing that the voice of a documentary about Gaza was the child of a Hamas representative, as ruled by regulatory body Ofcom.
An investigation by the broadcasting watchdog into the programme Gaza: How to Survive a Warzone has concluded that the documentary was "materially misleading".
The chief executive of the broadcaster had earlier expressed regret, noting there had been "a major oversight in relation to accuracy".
Ofcom has ordered the broadcaster to transmit a peak-time announcement about its findings.
"Given this constitutes a major infringement of our code, we are ordering the corporation to air a statement of our conclusions against it on BBC Two at nine o'clock in the evening, with a schedule to be determined," it said.
'Possibility to Erode Confidence'
The regulator's report stated: "Our probe concluded that the programme's omission to reveal that the narrator's father held a post in the Hamas-controlled administration was substantially inaccurate.
"It meant that the viewers did not have critical information which may have been very significant to their judgment of the narrator and the information he presented.
"Confidence is at the core of the bond between a television network and its audience, notably for a public service broadcaster such as the BBC.
"This failing had the risk to erode the very considerable amounts of trust that the public would have placed in a documentary produced by the BBC about the Gaza conflict."
The programme was withdrawn from the online platform in February after the narrator's family links were revealed, and in July an internal BBC review found it infringed the corporation's editorial guidelines on truthfulness.
A representative for the broadcaster stated: "The regulator's decision is in line with the findings of the internal assessment, that there was a major oversight in the film in relation to the broadcaster's journalistic policies on truthfulness, which reflects Rule 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we agree with Ofcom's decision in complete. We will follow the directive as soon as the timing and wording are finalised."
