The British broadcaster committed a "major breach" of media regulations by failing to disclose that the voice of a programme about Gaza was the child of a Hamas official, according to regulatory body Ofcom.
An investigation by Ofcom into Gaza: How to Survive a Warzone has found that the documentary was "materially misleading".
The chief executive of the broadcaster had already issued an apology, stating there had been "a major oversight in relation to truthfulness".
Ofcom has ordered the broadcaster to air a peak-time announcement about its findings.
"Since this amounts to a serious breach of our code, we are directing the BBC to broadcast a statement of our findings against it on the BBC's second channel at nine o'clock in the evening, with a timing to be finalised," it said.
'Possibility to Undermine Credibility'
The watchdog's statement stated: "Our investigation determined that the film's omission to reveal that the voice's parent held a post in the Hamas-administered authority was materially misleading.
"Consequently that the audience did not have essential details which may have been extremely pertinent to their assessment of the narrator and the information he presented.
"Credibility is at the heart of the bond between a broadcaster and its public, particularly for a public service broadcaster such as the BBC.
"This error had the potential to damage the very considerable degrees of confidence that the public would have invested in a documentary produced by the BBC about the Israel-Gaza war."
The programme was pulled from the online platform in last February after the boy's family links emerged, and in this past July an corporation's own inquiry found it breached the organization's journalistic standards on truthfulness.
A representative for the broadcaster said: "The authority's determination is in accordance with the findings of the corporation's inquiry, that there was a serious error in the documentary in relation to the BBC's Editorial Guidelines on accuracy, which reflects regulation 2.2 of the authority's broadcasting regulations.
"We have apologised for this and we comply with the regulator's ruling in its entirety. We will comply with the sanction as soon as the timing and wording are determined."
