The British broadcaster committed a "significant breach" of industry standards by not revealing that the voice of a film about the Gaza situation was the offspring of a Hamas administrator, as ruled by British broadcasting authority Ofcom.
An probe by the media regulator into the programme Gaza: How to Survive a Warzone has found that the film was "significantly deceptive".
The BBC's director general had earlier expressed regret, stating there had been "a significant failing in relation to truthfulness".
The regulator has instructed the broadcaster to broadcast a peak-time announcement about its decisions.
"Since this amounts to a serious breach of our regulations, we are directing the BBC to air a statement of our conclusions against it on BBC Two at 9pm, with a schedule to be finalised," it said.
'Possibility to Damage Confidence'
The regulator's statement stated: "The inquiry we conducted concluded that the programme's failure to disclose that the voice's parent served in a role in the Hamas-run authority was significantly deceptive.
"Consequently that the public did not have vital facts which may have been very significant to their judgment of the narrator and the content he shared.
"Confidence is at the center of the relationship between a media organization and its public, notably for a national broadcasting corporation such as the BBC.
"This oversight had the potential to undermine the very considerable levels of confidence that the public would have put in a BBC factual programme about the Gaza conflict."
The film was removed from iPlayer in last February after the boy's family links came to light, and in this past July an broadcaster's internal assessment concluded it breached the organization's journalistic standards on truthfulness.
A BBC spokesperson stated: "The Ofcom ruling is in accordance with the findings of the internal assessment, that there was a significant failing in the documentary in relation to the BBC's Editorial Guidelines on accuracy, which corresponds to regulation 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we agree with the authority's determination in complete. We will comply with the penalty as soon as the timing and wording are determined."