The BBC engaged in a "serious breach" of media regulations by failing to disclose that the voice of a film about the Gaza conflict was the offspring of a Hamas representative, according to regulatory body Ofcom.
An inquiry by the media regulator into the programme Gaza: How to Survive a Warzone has found that the programme was "materially misleading".
The BBC's director general had already issued an apology, noting there had been "a serious error in relation to accuracy".
The regulator has ordered the BBC to broadcast a evening declaration about its findings.
"As this represents a significant violation of our rules, we are directing the broadcaster to broadcast a message of our determinations against it on BBC2 at nine o'clock in the evening, with a schedule to be determined," the statement read.
'Risk to Erode Confidence'
The watchdog's report declared: "The inquiry we conducted found that the film's failure to disclose that the voice's father occupied a position in the Hamas-run authority was substantially inaccurate.
"It meant that the viewers did not have vital facts which may have been extremely pertinent to their evaluation of the presenter and the content he presented.
"Credibility is at the heart of the bond between a television network and its audience, particularly for a national broadcasting corporation such as the BBC.
"This failing had the risk to erode the exceptionally strong levels of credibility that viewers would have invested in a documentary produced by the BBC about the Gaza conflict."
The documentary was pulled from the BBC's streaming service in February after the boy's personal associations emerged, and in July an broadcaster's internal assessment found it violated the organization's content policies on factual correctness.
A BBC spokesperson stated: "The authority's determination is in agreement with the results of the internal assessment, that there was a significant failing in the film in relation to the corporation's content standards on truthfulness, which aligns with Rule 2.2 of the authority's broadcasting regulations.
"We have apologised for this and we comply with the regulator's ruling in its entirety. We will follow the penalty as soon as the timing and wording are confirmed."
