The BBC engaged in a "major breach" of industry standards by omitting to mention that the voice of a film about the Gaza conflict was the child of a Hamas official, according to British broadcasting authority Ofcom.
An investigation by the media regulator into the programme Gaza: How to Survive a Warzone has found that the programme was "significantly deceptive".
The head of the BBC had earlier expressed regret, noting there had been "a major oversight in relation to truthfulness".
The authority has instructed the BBC to broadcast a peak-time declaration about its conclusions.
"Since this amounts to a significant violation of our code, we are directing the BBC to transmit a statement of our determinations against it on BBC Two at nine o'clock in the evening, with a timing to be finalised," the statement read.
'Possibility to Erode Credibility'
The watchdog's report declared: "The inquiry we conducted concluded that the programme's lack of disclosure that the narrator's father occupied a role in the Hamas-run administration was substantially inaccurate.
"This implied that the audience did not have vital facts which may have been highly relevant to their judgment of the narrator and the content he shared.
"Trust is at the heart of the connection between a broadcaster and its public, notably for a national broadcasting corporation such as the BBC.
"This failing had the potential to damage the significantly high levels of confidence that the public would have invested 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 familial connections emerged, and in the month of July an broadcaster's internal assessment determined it violated the organization's editorial guidelines on truthfulness.
A BBC spokesperson commented: "The authority's determination is in agreement with the results of the internal assessment, 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 issued an apology for this and we comply with Ofcom's decision in its entirety. We will follow the directive as soon as the date and wording are determined."
