The British broadcaster engaged in a "serious breach" of media regulations by omitting to mention that the voice of a documentary about Gaza was the child of a Hamas administrator, as determined by British broadcasting authority Ofcom.
An inquiry by Ofcom into the programme Gaza: How to Survive a Warzone has found that the film was "materially misleading".
The chief executive of the broadcaster had previously apologised, noting there had been "a major oversight in relation to accuracy".
Ofcom has instructed the BBC to transmit a peak-time announcement about its findings.
"Given this constitutes a major infringement of our code, we are ordering the broadcaster to broadcast a announcement of our conclusions against it on BBC Two at 9pm, with a date to be determined," it said.
'Potential to Undermine Credibility'
The authority's report said: "The inquiry we conducted determined that the documentary's omission to reveal that the presenter's male guardian served in a post in the Hamas-controlled administration was substantially inaccurate.
"This implied that the viewers did not have essential details which may have been very significant to their judgment of the presenter and the information he shared.
"Trust is at the center of the bond between a television network and its audience, particularly for a public service broadcaster such as the BBC.
"This error had the possibility to undermine the very considerable levels of credibility that the public would have placed in a documentary produced by the BBC about the conflict in Gaza."
The film was removed from the BBC's streaming service in last February after the boy's family links came to light, and in July an broadcaster's internal assessment found it breached the corporation's journalistic standards on factual correctness.
A BBC spokesperson said: "The regulator's decision is in accordance with the results of Peter Johnston's review, that there was a serious error in the film in relation to the BBC's Editorial Guidelines on accuracy, which corresponds to Rule 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we accept the authority's determination in its entirety. We will adhere to the sanction as soon as the timing and language are determined."
