The public service broadcaster engaged in a "serious breach" of media regulations by failing to disclose that the voice of a film about the Gaza conflict was the child of a Hamas administrator, as determined by UK media regulator Ofcom.
An inquiry by Ofcom into the programme Gaza: How to Survive a Warzone has found that the film was "substantially inaccurate".
The chief executive of the broadcaster had already issued an apology, saying there had been "a significant failing in relation to accuracy".
The authority has instructed the corporation to broadcast a prime-time announcement about its findings.
"As this represents a serious breach of our code, we are directing the broadcaster to broadcast a announcement of our conclusions against it on BBC Two at 21:00, with a timing to be confirmed," the statement read.
'Possibility to Undermine Trust'
The authority's statement said: "Our investigation found that the film's lack of disclosure that the narrator's parent held a position in the Hamas-administered authority was significantly deceptive.
"Consequently that the viewers did not have critical information which may have been highly relevant to their evaluation of the presenter and the content he presented.
"Confidence is at the heart of the connection between a broadcaster and its audience, especially for a public service broadcaster such as the British Broadcasting Corporation.
"This error had the potential to damage the significantly high levels of confidence that viewers would have invested in a factual film from the broadcaster about the Israel-Gaza war."
The film was withdrawn from the BBC's streaming service in the month of February after the boy's familial connections were revealed, and in this past July an internal BBC review concluded it breached the broadcaster's journalistic standards on truthfulness.
A representative for the broadcaster said: "The authority's determination is in line with the results of Peter Johnston's review, that there was a serious error in the programme in relation to the broadcaster's journalistic policies on truthfulness, which reflects clause 2.2 of the regulator's media standards.
"We expressed regret for this and we comply with the regulator's ruling in complete. We will adhere to the penalty as soon as the timing and wording are determined."
