The public service broadcaster committed a "significant breach" of industry standards by omitting to mention that the narrator of a programme about the Gaza situation was the son of a Hamas administrator, according to regulatory body Ofcom.
An inquiry by the media regulator into the documentary titled Gaza: How to Survive a Warzone has found that the film was "materially misleading".
The head of the BBC had already issued an apology, noting there had been "a serious error in relation to factual correctness".
The regulator has instructed the corporation to air a prime-time declaration about its findings.
"As this represents a serious breach of our rules, we are directing the BBC to air a statement of our conclusions against it on BBC2 at nine o'clock in the evening, with a date to be finalised," it said.
'Possibility to Undermine Confidence'
The watchdog's report stated: "The inquiry we conducted concluded that the film's omission to reveal that the narrator's parent held a post in the Hamas-controlled authority was materially misleading.
"This implied that the viewers did not have critical information which may have been very significant to their evaluation of the voice and the details he provided.
"Trust is at the center of the relationship between a media organization and its viewers, particularly for a state-funded media outlet such as the British Broadcasting Corporation.
"This failing had the risk to erode the exceptionally strong degrees of credibility that viewers would have put in a BBC factual programme about the conflict in Gaza."
The film was pulled from the online platform in February after the boy's familial connections emerged, and in the month of July an internal BBC review concluded it infringed the corporation's journalistic standards on accuracy.
A representative for the broadcaster stated: "The authority's determination is in accordance with the conclusions of the corporation's inquiry, that there was a serious error in the film in relation to the broadcaster's journalistic policies on factual correctness, which reflects clause 2.2 of Ofcom's Broadcasting Code.
"We expressed regret for this and we agree with the regulator's ruling in full. We will comply with the sanction as soon as the timing and wording are finalised."
