The BBC engaged in a "serious breach" of broadcasting rules by not revealing that the voice of a documentary about Gaza was the son of a Hamas administrator, according to UK media regulator Ofcom.
An inquiry by the broadcasting watchdog 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, saying there had been "a significant failing in relation to factual correctness".
Ofcom has directed the BBC to air a evening declaration about its findings.
"Since this amounts to a serious breach of our rules, we are ordering the BBC to transmit a statement of our findings against it on BBC Two at 9pm, with a date to be confirmed," the statement read.
'Potential to Erode Confidence'
The authority's statement stated: "Our investigation determined that the film's lack of disclosure that the presenter's male guardian held a post in the Hamas-run administration was significantly deceptive.
"This implied that the public did not have essential details which may have been highly relevant to their judgment of the presenter and the details he shared.
"Confidence is at the core of the relationship between a media organization and its viewers, particularly for a state-funded media outlet such as the BBC.
"This error had the possibility to erode the exceptionally strong degrees of trust that the public would have put in a BBC factual programme about the conflict in Gaza."
The film was withdrawn from the BBC's streaming service in the month of February after the boy's familial connections came to light, and in the month of July an internal BBC review found it infringed the organization's journalistic standards on truthfulness.
A representative for the broadcaster said: "The authority's determination is in line with the findings of the internal assessment, that there was a serious error in the film in relation to the corporation's content standards on truthfulness, which aligns with regulation 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we comply with the authority's determination in full. We will follow the directive as soon as the timing and language are determined."
