The British broadcaster engaged in a "significant breach" of industry standards by omitting to mention that the voice of a film about the Gaza conflict was the son of a Hamas official, as ruled by regulatory body Ofcom.
An probe by the media regulator into Gaza: How to Survive a Warzone has determined that the documentary was "substantially inaccurate".
The BBC's director general had already issued an apology, saying there had been "a significant failing in relation to accuracy".
Ofcom has instructed the corporation to broadcast a evening announcement about its conclusions.
"Given this constitutes a major infringement of our regulations, we are instructing the broadcaster to transmit a announcement of our conclusions against it on BBC Two at 9pm, with a timing to be finalised," the regulator stated.
'Potential to Damage Trust'
The authority's report stated: "Our probe determined that the programme's omission to reveal that the voice's male guardian held a role in the Hamas-run government was substantially inaccurate.
"Consequently that the audience did not have critical information which may have been extremely pertinent to their judgment of the narrator and the content he provided.
"Credibility is at the heart of the connection between a media organization and its viewers, notably for a national broadcasting corporation such as the BBC.
"This error had the possibility to undermine the significantly high amounts of credibility that audiences would have placed in a documentary produced by the BBC about the Israel-Gaza war."
The documentary was removed from the online platform in last February after the boy's family links emerged, and in the month of July an broadcaster's internal assessment concluded it violated the broadcaster's editorial guidelines on factual correctness.
A corporation official said: "The authority's determination is in line with the findings of the internal assessment, that there was a serious error in the documentary in relation to the BBC's Editorial Guidelines on accuracy, which aligns with regulation 2.2 of the regulator's media standards.
"We expressed regret for this and we agree with the authority's determination in complete. We will follow the sanction as soon as the schedule and language are finalised."
