The BBC committed a "significant breach" of media regulations by failing to disclose that the narrator of a film about Gaza was the son of a Hamas administrator, according to regulatory body Ofcom.
An probe by the media regulator into Gaza: How to Survive a Warzone has determined that the film was "materially misleading".
The BBC's director general had previously apologised, noting there had been "a serious error in relation to accuracy".
Ofcom has directed the BBC to broadcast a peak-time announcement about its findings.
"As this represents a significant violation of our code, we are directing the corporation to air a statement of our conclusions against it on the BBC's second channel at 9pm, with a date to be finalised," the regulator stated.
'Risk to Undermine Credibility'
The watchdog's announcement said: "The inquiry we conducted concluded that the programme's failure to disclose that the presenter's male guardian occupied a role in the Hamas-administered government was significantly deceptive.
"It meant that the audience did not have vital facts which may have been very significant to their judgment of the presenter and the information he shared.
"Trust is at the heart of the relationship between a broadcaster and its audience, especially for a national broadcasting corporation such as the BBC.
"This error had the potential to damage the exceptionally strong levels of credibility that the public would have invested in a documentary produced by the BBC about the Gaza conflict."
The programme was removed from the BBC's streaming service in February after the narrator's familial connections came to light, and in the month of July an internal BBC review found it violated the broadcaster's journalistic standards on accuracy.
A corporation official commented: "The Ofcom ruling is in accordance with the conclusions of the corporation's inquiry, that there was a serious error in the film in relation to the corporation's content standards on truthfulness, which corresponds to regulation 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we accept Ofcom's decision in complete. We will comply with the penalty as soon as the date and language are confirmed."
