The public service broadcaster was found to have committed a "major breach" of broadcasting rules by not revealing that the narrator of a programme about the Gaza conflict was the offspring of a Hamas representative, according to UK media regulator Ofcom.
An investigation by the broadcasting watchdog into Gaza: How to Survive a Warzone has found that the documentary was "substantially inaccurate".
The head of the BBC had earlier expressed regret, noting there had been "a major oversight in relation to truthfulness".
Ofcom has ordered the BBC to broadcast a peak-time declaration about its conclusions.
"Since this amounts to a significant violation of our rules, we are ordering 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 date to be confirmed," the statement read.
'Risk to Damage Confidence'
The watchdog's announcement stated: "The inquiry we conducted concluded that the programme's failure to disclose that the voice's male guardian served in a post in the Hamas-controlled government was substantially inaccurate.
"It meant that the viewers did not have vital facts which may have been highly relevant to their assessment of the presenter and the information he provided.
"Trust is at the center of the relationship between a television network and its viewers, especially for a state-funded media outlet such as the public broadcaster.
"This error had the risk to erode the exceptionally strong levels of credibility that audiences would have placed in a BBC factual programme about the conflict in Gaza."
The programme was removed from the BBC's streaming service in last February after the presenter's personal associations emerged, and in July an internal BBC review determined it violated the broadcaster's content policies on truthfulness.
A representative for the broadcaster said: "The Ofcom ruling is in accordance with the findings of the corporation's inquiry, that there was a major oversight in the film in relation to the broadcaster's journalistic policies on factual correctness, which corresponds to Rule 2.2 of Ofcom's Broadcasting Code.
"We expressed regret for this and we accept Ofcom's decision in its entirety. We will comply with the sanction as soon as the date and wording are finalised."
