The BBC engaged in a "major breach" of industry standards by not revealing that the voice of a programme about Gaza was the son of a Hamas official, as determined by British broadcasting authority Ofcom.
An investigation by the broadcasting watchdog into the programme Gaza: How to Survive a Warzone has found that the film was "substantially inaccurate".
The chief executive of the broadcaster had earlier expressed regret, stating there had been "a significant failing in relation to truthfulness".
The regulator has ordered the BBC to transmit a evening announcement about its findings.
"Given this constitutes a major infringement of our regulations, we are ordering the BBC to broadcast a statement of our conclusions against it on BBC2 at 21:00, with a schedule to be finalised," it said.
'Potential to Damage Confidence'
The authority's announcement declared: "The inquiry we conducted concluded that the documentary's omission to reveal that the voice's male guardian held a position in the Hamas-run administration was materially misleading.
"Consequently that the audience did not have vital facts which may have been very significant to their judgment of the voice and the content he presented.
"Confidence is at the heart of the connection between a media organization and its viewers, notably for a state-funded media outlet such as the public broadcaster.
"This error had the risk to undermine the significantly high levels of credibility that the public would have placed in a factual film from the broadcaster about the conflict in Gaza."
The film was pulled from iPlayer in February after the boy's personal associations emerged, and in July an internal BBC review found it breached the broadcaster's journalistic standards on factual correctness.
A representative for the broadcaster commented: "The authority's determination is in agreement with the findings of Peter Johnston's review, that there was a serious error in the film in relation to the broadcaster's journalistic policies on truthfulness, which aligns with Rule 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we agree with the regulator's ruling in full. We will follow the sanction as soon as the date and language are determined."
