The BBC engaged in a "significant breach" of broadcasting rules by not revealing that the voice of a programme about the Gaza conflict was the child of a Hamas administrator, according to UK media regulator Ofcom.
An probe by the media regulator into the programme Gaza: How to Survive a Warzone has determined that the programme was "significantly deceptive".
The head of the BBC had previously apologised, saying there had been "a major oversight in relation to factual correctness".
The authority has directed the corporation to transmit a prime-time announcement about its findings.
"As this represents a significant violation of our code, we are directing the broadcaster to broadcast a message of our determinations against it on BBC2 at 21:00, with a timing to be confirmed," it said.
'Possibility to Undermine Credibility'
The watchdog's announcement stated: "The inquiry we conducted found that the film's omission to reveal that the presenter's parent occupied a role in the Hamas-administered government was substantially inaccurate.
"It meant that the viewers did not have vital facts which may have been very significant to their judgment of the voice and the content he provided.
"Confidence is at the core of the relationship between a television network and its audience, notably for a public service broadcaster such as the British Broadcasting Corporation.
"This oversight had the risk to undermine the significantly high degrees of confidence that viewers would have placed in a documentary produced by the BBC about the conflict in Gaza."
The documentary was removed from the BBC's streaming service in the month of 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 accuracy.
A BBC spokesperson said: "The authority's determination is in agreement with the findings of the corporation's inquiry, that there was a major oversight in the documentary in relation to the corporation's content standards on truthfulness, which aligns with regulation 2.2 of the authority's broadcasting regulations.
"We have apologised for this and we accept the regulator's ruling in complete. We will adhere to the sanction as soon as the schedule and wording are finalised."
