The public service broadcaster was found to have committed a "significant breach" of media regulations by not revealing that the narrator of a film about the Gaza conflict was the child of a Hamas administrator, as determined by regulatory body Ofcom.
An inquiry by Ofcom into Gaza: How to Survive a Warzone has concluded that the film was "materially misleading".
The head of the BBC had already issued an apology, noting there had been "a major oversight in relation to accuracy".
The regulator has instructed the BBC to broadcast a prime-time declaration about its findings.
"As this represents a serious breach of our regulations, we are ordering the BBC to transmit a statement of our determinations against it on BBC Two at 21:00, with a timing to be confirmed," the regulator stated.
The watchdog's report declared: "Our investigation determined that the documentary's lack of disclosure that the voice's male guardian served in a role in the Hamas-run authority was materially misleading.
"It meant that the audience did not have essential details which may have been extremely pertinent to their judgment of the voice and the details he presented.
"Trust is at the heart of the bond between a media organization and its public, especially for a public service broadcaster such as the BBC.
"This oversight had the risk to erode the exceptionally strong levels of credibility that audiences would have placed in a documentary produced by the BBC about the Israel-Gaza war."
The documentary was removed from iPlayer in last February after the boy's familial connections came to light, and in this past July an corporation's own inquiry found it infringed the corporation's journalistic standards on accuracy.
A representative for the broadcaster stated: "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 broadcaster's journalistic policies on factual correctness, which reflects Rule 2.2 of the regulator's media standards.
"We have apologised for this and we comply with the authority's determination in complete. We will follow the penalty as soon as the date and wording are finalised."