The public service broadcaster committed a "significant breach" of broadcasting rules by not revealing that the voice of a film about the Gaza situation was the offspring of a Hamas representative, as ruled by regulatory body Ofcom.
An investigation by the media regulator into Gaza: How to Survive a Warzone has concluded that the documentary was "substantially inaccurate".
The chief executive of the broadcaster had earlier expressed regret, stating there had been "a significant failing in relation to accuracy".
The regulator has instructed the BBC to transmit a evening announcement about its findings.
"Given this constitutes a major infringement of our regulations, we are instructing the corporation to air a statement of our determinations against it on BBC Two at 9pm, with a date to be confirmed," it said.
'Risk to Damage Trust'
The watchdog's statement said: "The inquiry we conducted found that the film's lack of disclosure that the voice's parent held a position in the Hamas-administered authority was significantly deceptive.
"It meant that the audience did not have vital facts which may have been highly relevant to their judgment of the narrator and the content he shared.
"Confidence is at the center of the relationship between a broadcaster and its audience, especially for a public service broadcaster such as the BBC.
"This failing had the potential to undermine the exceptionally strong degrees of confidence that the public would have invested in a documentary produced by the BBC about the Israel-Gaza war."
The programme was removed from the online platform in last February after the boy's familial connections came to light, and in the month of July an broadcaster's internal assessment found it breached the broadcaster'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 programme in relation to the corporation's content standards on accuracy, which corresponds to clause 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we comply with the regulator's ruling in complete. We will comply with the penalty as soon as the date and wording are confirmed."
