The public service broadcaster committed a "serious breach" of broadcasting rules by not revealing that the narrator of a programme about the Gaza situation was the child of a Hamas representative, as ruled by regulatory body Ofcom.
An investigation by Ofcom into Gaza: How to Survive a Warzone has concluded that the programme was "substantially inaccurate".
The chief executive of the broadcaster had earlier expressed regret, noting there had been "a major oversight in relation to truthfulness".
The regulator has directed the corporation to broadcast a peak-time announcement about its conclusions.
"As this represents a major infringement of our regulations, we are directing the broadcaster to transmit a message of our findings against it on BBC Two at nine o'clock in the evening, with a timing to be finalised," it said.
'Potential to Erode Trust'
The regulator's report stated: "The inquiry we conducted determined that the documentary's omission to reveal that the presenter's male guardian occupied a post in the Hamas-controlled administration was materially misleading.
"Consequently that the audience did not have vital facts which may have been very significant to their judgment of the narrator and the content he shared.
"Confidence is at the center of the relationship between a television network and its public, particularly for a state-funded media outlet such as the public broadcaster.
"This error had the potential to undermine the exceptionally strong levels of confidence that audiences would have invested in a factual film from the broadcaster about the Israel-Gaza war."
The documentary was removed from iPlayer in February after the boy's personal associations were revealed, and in this past July an internal BBC review determined it violated the organization's journalistic standards on accuracy.
A representative for the broadcaster commented: "The Ofcom ruling is in agreement with the conclusions of Peter Johnston's review, that there was a serious error in the documentary in relation to the broadcaster's journalistic policies on factual correctness, which corresponds to clause 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we accept the regulator's ruling in full. We will adhere to the sanction as soon as the schedule and wording are confirmed."
