The BBC engaged in a "major breach" of broadcasting rules by failing to disclose that the voice of a programme about Gaza was the child of a Hamas representative, as determined by regulatory body Ofcom.
An investigation by the broadcasting watchdog into the documentary titled Gaza: How to Survive a Warzone has found that the film was "substantially inaccurate".
The head of the BBC had already issued an apology, noting there had been "a significant failing in relation to accuracy".
Ofcom has directed the corporation to transmit a peak-time announcement about its conclusions.
"Given this constitutes a serious breach of our rules, we are ordering the corporation to transmit a message of our conclusions against it on BBC2 at 9pm, with a schedule to be finalised," the regulator stated.
'Possibility to Erode Trust'
The authority's report said: "Our probe determined that the film's failure to disclose that the voice's male guardian occupied a post in the Hamas-run government was substantially inaccurate.
"Consequently that the viewers did not have critical information which may have been highly relevant to their assessment of the voice and the content he shared.
"Confidence is at the center of the relationship between a television network and its audience, especially for a public service broadcaster such as the British Broadcasting Corporation.
"This oversight had the risk to undermine the very considerable degrees of trust that audiences would have invested in a BBC factual programme about the conflict in Gaza."
The programme was pulled from the online platform in last February after the boy's familial connections were revealed, and in July an internal BBC review concluded it infringed the corporation's content policies on accuracy.
A BBC spokesperson said: "The regulator's decision is in agreement with the conclusions of Peter Johnston's review, that there was a significant failing in the film in relation to the broadcaster's journalistic policies on truthfulness, which corresponds to clause 2.2 of the regulator's media standards.
"We issued an apology for this and we agree with Ofcom's decision in full. We will comply with the sanction as soon as the timing and wording are determined."
