The BBC was found to have committed a "significant breach" of industry standards by omitting to mention that the voice of a documentary about the Gaza situation was the son of a Hamas administrator, as determined by regulatory body Ofcom.
An inquiry by the media regulator into Gaza: How to Survive a Warzone has determined that the programme was "significantly deceptive".
The BBC's director general had previously apologised, stating there had been "a major oversight in relation to accuracy".
The authority has ordered the corporation to broadcast a evening announcement about its conclusions.
"As this represents a major infringement of our code, we are directing the BBC to transmit a announcement of our findings against it on BBC2 at 21:00, with a schedule to be determined," it said.
'Potential to Undermine Credibility'
The watchdog's announcement declared: "Our investigation determined that the film's omission to reveal that the narrator's male guardian served in a role in the Hamas-administered government was significantly deceptive.
"Consequently that the viewers did not have critical information which may have been very significant to their judgment of the voice and the details he shared.
"Confidence is at the center of the relationship between a media organization and its audience, especially for a public service broadcaster such as the public broadcaster.
"This error had the potential to erode the significantly high amounts of credibility that audiences would have invested in a documentary produced by the BBC about the Israel-Gaza war."
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 infringed the corporation's editorial guidelines on truthfulness.
A BBC spokesperson said: "The Ofcom ruling is in accordance with the results of Peter Johnston's review, that there was a major oversight in the documentary in relation to the BBC's Editorial Guidelines on accuracy, which reflects clause 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we agree with the regulator's ruling in complete. We will adhere to the sanction as soon as the timing and wording are finalised."
