The public service broadcaster committed a "major breach" of industry standards by omitting to mention that the voice of a documentary about the Gaza situation was the son of a Hamas representative, according to UK media regulator Ofcom.
An inquiry by the media regulator into Gaza: How to Survive a Warzone has concluded that the programme was "materially misleading".
The BBC's director general had previously apologised, stating there had been "a significant failing in relation to accuracy".
The regulator has ordered the BBC to air a peak-time announcement about its conclusions.
"Given this constitutes a major infringement of our rules, we are ordering the broadcaster to transmit a announcement of our findings against it on BBC2 at 21:00, with a schedule to be confirmed," it said.
'Risk to Undermine Confidence'
The authority's announcement said: "Our probe concluded that the programme's lack of disclosure that the narrator's parent served in a position in the Hamas-administered government was materially misleading.
"Consequently that the public did not have essential details which may have been extremely pertinent to their judgment of the narrator and the content he presented.
"Confidence is at the core of the connection between a television network and its audience, especially for a public service broadcaster such as the British Broadcasting Corporation.
"This error had the risk to undermine the significantly high levels of credibility that viewers would have placed in a documentary produced by the BBC about the Gaza conflict."
The documentary was withdrawn from iPlayer in the month of February after the boy's family links emerged, and in this past July an corporation's own inquiry determined it breached the organization's journalistic standards on truthfulness.
A corporation official stated: "The Ofcom ruling is in agreement with the conclusions of Peter Johnston's review, that there was a serious error in the film in relation to the BBC's Editorial Guidelines on accuracy, which corresponds to Rule 2.2 of the regulator's media standards.
"We have apologised for this and we comply with Ofcom's decision in its entirety. We will follow the penalty as soon as the timing and wording are confirmed."
