The public service broadcaster engaged in a "significant breach" of industry standards by omitting to mention that the narrator of a programme about the Gaza conflict was the offspring of a Hamas administrator, as ruled by British broadcasting authority Ofcom.
An probe by Ofcom into Gaza: How to Survive a Warzone has concluded that the programme was "substantially inaccurate".
The head of the BBC had earlier expressed regret, noting there had been "a major oversight in relation to accuracy".
The authority has directed the broadcaster to broadcast a peak-time statement about its decisions.
"Since this amounts to a major infringement of our regulations, we are directing the corporation to air a announcement of our conclusions against it on BBC2 at 9pm, with a date to be determined," the regulator stated.
'Potential to Damage Trust'
The regulator's statement said: "Our probe determined that the documentary's lack of disclosure that the narrator's male guardian held a position in the Hamas-administered government was substantially inaccurate.
"It meant that the audience did not have critical information which may have been extremely pertinent to their evaluation of the presenter and the information he shared.
"Credibility is at the center of the relationship between a media organization and its viewers, notably for a national broadcasting corporation such as the British Broadcasting Corporation.
"This failing had the potential to erode the significantly high amounts of trust that the public would have put in a documentary produced by the BBC about the Gaza conflict."
The programme was withdrawn from the BBC's streaming service in last February after the narrator's family links were revealed, and in July an corporation's own inquiry found it violated the broadcaster's journalistic standards on truthfulness.
A corporation official stated: "The regulator's decision is in line with the findings of the internal assessment, that there was a serious error in the film in relation to the BBC's Editorial Guidelines on factual correctness, which aligns with clause 2.2 of the regulator's media standards.
"We expressed regret for this and we accept Ofcom's decision in complete. We will follow the sanction as soon as the date and wording are finalised."
