The British broadcaster engaged in a "major breach" of broadcasting rules by failing to disclose that the voice of a film about the Gaza situation was the son of a Hamas representative, as ruled by regulatory body Ofcom.
An inquiry by Ofcom into Gaza: How to Survive a Warzone has concluded that the documentary was "materially misleading".
The head of the BBC had earlier expressed regret, noting there had been "a significant failing in relation to factual correctness".
The regulator has instructed the BBC to broadcast a prime-time announcement about its findings.
"Given this constitutes a significant violation of our code, we are ordering the BBC to broadcast a statement of our conclusions against it on BBC Two at nine o'clock in the evening, with a schedule to be determined," it said.
'Risk to Undermine Credibility'
The regulator's statement stated: "The inquiry we conducted found that the film's failure to disclose that the voice's parent served in a role in the Hamas-controlled government was materially misleading.
"It meant that the audience did not have vital facts which may have been very significant to their evaluation of the narrator and the content he shared.
"Credibility is at the heart of the bond between a television network and its audience, notably for a national broadcasting corporation such as the BBC.
"This error had the possibility to damage the exceptionally strong amounts of credibility that viewers would have put in a BBC factual programme about the Gaza conflict."
The documentary was withdrawn from the online platform in last February after the boy's family links came to light, and in the month of July an corporation's own inquiry found it violated the corporation's content policies on accuracy.
A representative for the broadcaster said: "The authority's determination is in accordance with the conclusions of the corporation's inquiry, that there was a major oversight in the programme in relation to the broadcaster's journalistic policies on factual correctness, which reflects Rule 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we accept the regulator's ruling in complete. We will adhere to the penalty as soon as the timing and wording are determined."
