The public service broadcaster was found to have committed a "significant breach" of broadcasting rules by not revealing that the presenter of a documentary about Gaza was the offspring of a Hamas representative, according to regulatory body Ofcom.
An inquiry by Ofcom into the programme Gaza: How to Survive a Warzone has concluded that the programme was "materially misleading".
The chief executive of the broadcaster had earlier expressed regret, noting there had been "a serious error in relation to accuracy".
The regulator has instructed the BBC to air a peak-time announcement about its conclusions.
"As this represents a significant violation of our code, we are instructing the corporation to air a announcement of our findings against it on BBC Two at 9pm, with a schedule to be determined," the regulator stated.
'Possibility to Erode Confidence'
The regulator's report stated: "Our investigation concluded that the documentary's lack of disclosure that the voice's male guardian occupied a post in the Hamas-administered authority was substantially inaccurate.
"This implied that the audience did not have essential details which may have been highly relevant to their judgment of the narrator and the content he provided.
"Trust is at the center of the relationship between a media organization and its audience, especially for a state-funded media outlet such as the British Broadcasting Corporation.
"This oversight had the risk to undermine the exceptionally strong amounts of credibility that audiences would have invested in a documentary produced by the BBC about the conflict in Gaza."
The documentary was withdrawn from iPlayer in last February after the narrator's personal associations were revealed, and in the month of July an broadcaster's internal assessment concluded it breached the broadcaster's journalistic standards on accuracy.
A representative for the broadcaster said: "The regulator's decision is in agreement with the findings of Peter Johnston's review, that there was a serious error in the programme in relation to the BBC's Editorial Guidelines on accuracy, which corresponds to clause 2.2 of the regulator's media standards.
"We issued an apology for this and we accept the regulator's ruling in its entirety. We will adhere to the directive as soon as the schedule and language are finalised."
