The British broadcaster engaged in a "major breach" of broadcasting rules by not revealing that the voice of a programme about the Gaza conflict was the offspring of a Hamas representative, as determined by British broadcasting authority Ofcom.
An probe by the broadcasting watchdog into the programme Gaza: How to Survive a Warzone has found that the programme was "substantially inaccurate".
The BBC's director general had previously apologised, noting there had been "a serious error in relation to factual correctness".
The regulator has directed the BBC to air a evening declaration about its conclusions.
"As this represents a major infringement of our code, we are directing the corporation to transmit a statement of our findings against it on BBC Two at nine o'clock in the evening, with a schedule to be finalised," the regulator stated.
'Possibility to Undermine Credibility'
The watchdog's announcement declared: "The inquiry we conducted found that the film's failure to disclose that the voice's male guardian served in a position in the Hamas-controlled authority was materially misleading.
"It meant that the audience did not have critical information which may have been very significant to their evaluation of the narrator and the content he provided.
"Credibility is at the core of the relationship between a media organization and its viewers, notably for a state-funded media outlet such as the British Broadcasting Corporation.
"This error had the risk to erode the significantly high degrees of trust that audiences would have invested in a BBC factual programme about the Israel-Gaza war."
The documentary was pulled from the online platform in February after the narrator's personal associations emerged, and in July an broadcaster's internal assessment found it breached the broadcaster's editorial guidelines on truthfulness.
A representative for the broadcaster stated: "The regulator's decision is in accordance with the findings of Peter Johnston's review, that there was a serious error in the programme in relation to the corporation's content standards on truthfulness, which aligns with clause 2.2 of the regulator's media standards.
"We have apologised for this and we agree with the regulator's ruling in full. We will follow the penalty as soon as the date and wording are determined."
