The public service broadcaster was found to have committed a "major breach" of media regulations by failing to disclose that the narrator of a film about the Gaza conflict was the son of a Hamas official, as determined by British broadcasting authority Ofcom.
An investigation by Ofcom into Gaza: How to Survive a Warzone has concluded that the film was "substantially inaccurate".
The BBC's director general had earlier expressed regret, saying there had been "a serious error in relation to truthfulness".
The authority has directed the corporation to broadcast a prime-time statement about its conclusions.
"Since this amounts to a serious breach of our regulations, we are instructing the corporation to air a announcement of our determinations against it on BBC Two at 9pm, with a timing to be confirmed," the statement read.
'Risk to Undermine Trust'
The watchdog's report declared: "Our probe concluded that the programme's failure to disclose that the presenter's male guardian held a role in the Hamas-controlled government was significantly deceptive.
"This implied that the audience did not have critical information which may have been highly relevant to their judgment of the narrator and the content he presented.
"Confidence is at the center of the relationship between a television network and its audience, particularly for a public service broadcaster such as the British Broadcasting Corporation.
"This oversight had the potential to erode the significantly high levels of confidence that the public would have invested in a factual film from the broadcaster about the conflict in Gaza."
The documentary was pulled from the BBC's streaming service in last February after the boy's familial connections came to light, and in July an internal BBC review concluded it violated the corporation's journalistic standards on truthfulness.
A BBC spokesperson stated: "The authority's determination is in line with the findings of the internal assessment, that there was a significant failing in the documentary in relation to the corporation's content standards on truthfulness, which aligns with clause 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we agree with Ofcom's decision in full. We will follow the sanction as soon as the schedule and wording are confirmed."
