The public service broadcaster engaged in a "serious breach" of broadcasting rules by not revealing that the narrator of a programme about Gaza was the son of a Hamas representative, as determined by British broadcasting authority Ofcom.
An inquiry by Ofcom into the programme Gaza: How to Survive a Warzone has determined that the film was "materially misleading".
The head of the BBC had already issued an apology, noting there had been "a serious error in relation to factual correctness".
The authority has directed the broadcaster to air a peak-time declaration about its findings.
"Since this amounts to a significant violation of our rules, we are ordering the corporation to air a message of our conclusions against it on BBC Two at 9pm, with a timing to be finalised," the regulator stated.
'Potential to Undermine Trust'
The regulator's announcement stated: "The inquiry we conducted found that the documentary's failure to disclose that the voice's male guardian served in a position in the Hamas-run government was significantly deceptive.
"It meant that the public did not have vital facts which may have been highly relevant to their evaluation of the presenter and the information he shared.
"Trust is at the heart of the bond between a broadcaster and its public, notably for a state-funded media outlet such as the British Broadcasting Corporation.
"This failing had the possibility to damage the very considerable levels of credibility that the public would have placed in a documentary produced by the BBC about the Israel-Gaza war."
The documentary was withdrawn from the BBC's streaming service in the month of February after the boy's personal associations came to light, and in July an corporation's own inquiry found it violated the corporation's content policies on factual correctness.
A corporation official said: "The regulator's decision is in agreement with the results of Peter Johnston's review, that there was a serious error in the documentary in relation to the corporation's content standards on factual correctness, which reflects clause 2.2 of Ofcom's Broadcasting Code.
"We expressed regret for this and we comply with the authority's determination in complete. We will adhere to the directive as soon as the schedule and wording are finalised."
