The British broadcaster engaged in a "major breach" of broadcasting rules by failing to disclose that the presenter of a film about Gaza was the offspring of a Hamas representative, according to British broadcasting authority Ofcom.
An probe by the media regulator into Gaza: How to Survive a Warzone has concluded that the film was "substantially inaccurate".
The head of the BBC had previously apologised, saying there had been "a major oversight in relation to truthfulness".
Ofcom has ordered the BBC to broadcast a peak-time announcement about its decisions.
"As this represents a major infringement of our regulations, we are instructing the BBC to air a message of our determinations against it on BBC Two at 9pm, with a timing to be finalised," it said.
'Potential to Damage Confidence'
The regulator's announcement declared: "Our probe concluded that the programme's omission to reveal that the voice's male guardian held a post in the Hamas-controlled government was significantly deceptive.
"This implied that the audience did not have vital facts which may have been very significant to their assessment of the presenter and the content he presented.
"Credibility is at the center of the relationship between a broadcaster and its viewers, particularly for a state-funded media outlet such as the BBC.
"This failing had the risk to undermine the exceptionally strong amounts of credibility that the public would have invested in a factual film from the broadcaster about the conflict in Gaza."
The film was removed from the BBC's streaming service in last February after the narrator's familial connections emerged, and in this past July an internal BBC review found it breached the corporation's editorial guidelines on factual correctness.
A corporation official said: "The Ofcom ruling is in accordance with the results of Peter Johnston's review, that there was a significant failing in the programme in relation to the corporation's content standards on truthfulness, which aligns with Rule 2.2 of the regulator's media standards.
"We expressed regret for this and we agree with the regulator's ruling in full. We will adhere to the directive as soon as the schedule and wording are confirmed."