The BBC engaged in a "significant breach" of media regulations by not revealing that the narrator of a film about the Gaza situation was the offspring of a Hamas administrator, as determined by UK media regulator Ofcom.
An probe by the media regulator into Gaza: How to Survive a Warzone has determined that the programme was "substantially inaccurate".
The chief executive of the broadcaster had already issued an apology, noting there had been "a major oversight in relation to factual correctness".
Ofcom has ordered the broadcaster to broadcast a peak-time declaration about its conclusions.
"Since this amounts to a serious breach of our code, we are directing the broadcaster to air a message of our findings against it on the BBC's second channel at nine o'clock in the evening, with a date to be determined," it said.
'Potential to Undermine Credibility'
The regulator's statement said: "The inquiry we conducted found that the programme's failure to disclose that the presenter's male guardian served in a role in the Hamas-administered authority was materially misleading.
"This implied that the public did not have essential details which may have been highly relevant to their judgment of the voice and the content he shared.
"Trust is at the heart of the relationship between a broadcaster and its audience, notably for a public service broadcaster such as the public broadcaster.
"This failing had the potential to erode the significantly high degrees of credibility that viewers would have invested in a BBC factual programme about the Israel-Gaza war."
The documentary was removed from the online platform in last February after the boy's personal associations came to light, and in this past July an internal BBC review concluded it violated the corporation's journalistic standards on truthfulness.
A corporation official said: "The authority's determination is in line with the results of Peter Johnston's review, that there was a significant failing in the documentary in relation to the broadcaster's journalistic policies on factual correctness, which reflects clause 2.2 of the regulator's media standards.
"We have apologised for this and we comply with Ofcom's decision in full. We will follow the penalty as soon as the schedule and wording are determined."
