The BBC was found to have committed a "significant breach" of media regulations by failing to disclose that the voice of a programme about the Gaza conflict was the child of a Hamas representative, as ruled by UK media regulator Ofcom.
An inquiry by Ofcom into Gaza: How to Survive a Warzone has determined that the documentary was "significantly deceptive".
The head of the BBC had earlier expressed regret, saying there had been "a major oversight in relation to accuracy".
The authority has instructed the corporation to broadcast a peak-time declaration about its findings.
"Since this amounts to a serious breach of our rules, we are ordering the BBC to broadcast a announcement of our findings against it on BBC Two at nine o'clock in the evening, with a schedule to be finalised," the statement read.
'Risk to Undermine Confidence'
The watchdog's report declared: "Our investigation concluded that the documentary's failure to disclose that the voice's male guardian held a role in the Hamas-administered administration was materially misleading.
"Consequently that the public did not have critical information which may have been extremely pertinent to their evaluation of the voice and the details he presented.
"Trust is at the heart of the relationship between a broadcaster and its viewers, particularly for a public service broadcaster such as the British Broadcasting Corporation.
"This oversight had the possibility to undermine the significantly high degrees of confidence that audiences would have placed in a documentary produced by the BBC about the Israel-Gaza war."
The programme was removed from iPlayer in February after the boy's personal associations emerged, and in July an internal BBC review concluded it breached the broadcaster's journalistic standards on truthfulness.
A representative for the broadcaster stated: "The regulator's decision is in agreement with the conclusions of the internal assessment, that there was a serious error in the film in relation to the corporation's content standards on truthfulness, which corresponds to regulation 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we comply with Ofcom's decision in full. We will adhere to the directive as soon as the timing and wording are determined."
