The BBC committed a "significant breach" of industry standards by not revealing that the narrator of a documentary about Gaza was the child of a Hamas representative, as determined by UK media regulator Ofcom.
An inquiry by Ofcom into Gaza: How to Survive a Warzone has found that the programme was "substantially inaccurate".
The BBC's director general had earlier expressed regret, noting there had been "a major oversight in relation to factual correctness".
Ofcom has directed the corporation to air a prime-time announcement about its conclusions.
"Given this constitutes a significant violation of our regulations, we are directing the corporation to transmit a message of our determinations against it on BBC2 at 9pm, with a schedule to be confirmed," it said.
'Possibility to Undermine Credibility'
The authority's announcement stated: "The inquiry we conducted concluded that the documentary's lack of disclosure that the presenter's male guardian served in a position in the Hamas-run authority was materially misleading.
"This implied that the viewers did not have critical information which may have been extremely pertinent to their evaluation of the narrator and the content he presented.
"Confidence is at the core of the relationship between a media organization and its viewers, particularly for a public service broadcaster such as the British Broadcasting Corporation.
"This error had the possibility to damage the very considerable amounts of credibility that viewers would have placed in a factual film from the broadcaster about the conflict in Gaza."
The film was pulled from the online platform in the month of February after the boy's personal associations came to light, and in the month of July an internal BBC review found it breached the organization's content policies on accuracy.
A representative for the broadcaster stated: "The regulator's decision is in accordance with the findings of the internal assessment, that there was a major oversight in the programme in relation to the broadcaster's journalistic policies on truthfulness, which aligns with regulation 2.2 of Ofcom's Broadcasting Code.
"We expressed regret for this and we accept the authority's determination in its entirety. We will follow the sanction as soon as the timing and wording are finalised."
