The BBC committed a "major breach" of broadcasting rules by not revealing that the narrator of a programme about the Gaza conflict was the child of a Hamas official, according to UK media regulator Ofcom.
An inquiry by the media regulator into Gaza: How to Survive a Warzone has found that the film was "materially misleading".
The head of the BBC had earlier expressed regret, noting there had been "a serious error in relation to factual correctness".
The authority has directed the broadcaster to transmit a prime-time statement about its decisions.
"As this represents a significant violation of our rules, we are directing the broadcaster to air a message of our conclusions against it on the BBC's second channel at nine o'clock in the evening, with a schedule to be finalised," the regulator stated.
'Potential to Erode Confidence'
The regulator's report stated: "Our investigation concluded that the programme's omission to reveal that the voice's male guardian held a position in the Hamas-run authority was significantly deceptive.
"This implied that the audience did not have critical information which may have been very significant to their judgment of the presenter and the details he provided.
"Credibility is at the heart of the connection between a broadcaster and its viewers, particularly for a national broadcasting corporation such as the BBC.
"This error had the possibility to undermine the very considerable amounts of credibility that audiences would have placed in a BBC factual programme about the Gaza conflict."
The programme was pulled from iPlayer in February after the presenter's personal associations emerged, and in the month of July an internal BBC review determined it infringed the organization's journalistic standards on accuracy.
A corporation official said: "The regulator's decision is in agreement with the findings of the internal assessment, that there was a major oversight in the film in relation to the BBC's Editorial Guidelines on accuracy, which aligns with Rule 2.2 of the regulator's media standards.
"We expressed regret for this and we comply with the regulator's ruling in full. We will comply with the penalty as soon as the schedule and wording are finalised."
