The BBC was found to have committed a "significant breach" of industry standards by failing to disclose that the voice of a documentary about Gaza was the child of a Hamas official, according to regulatory body Ofcom.
An inquiry by the media regulator into Gaza: How to Survive a Warzone has concluded that the documentary was "materially misleading".
The head of the BBC had previously apologised, stating there had been "a serious error in relation to accuracy".
The regulator has ordered the broadcaster to air a evening announcement about its findings.
"Since this amounts to a major infringement of our code, we are instructing the BBC to transmit a message of our conclusions against it on the BBC's second channel at 21:00, with a schedule to be determined," the statement read.
'Possibility to Erode Trust'
The authority's statement said: "Our investigation found that the film's omission to reveal that the presenter's father served in a role in the Hamas-controlled government was significantly deceptive.
"This implied that the viewers did not have vital facts which may have been highly relevant to their judgment of the narrator and the content he presented.
"Trust is at the core of the relationship between a television network and its audience, especially for a national broadcasting corporation such as the British Broadcasting Corporation.
"This error had the potential to erode the very considerable degrees of trust that audiences would have put in a BBC factual programme about the Gaza conflict."
The programme was pulled from the online platform in the month of February after the boy's personal associations were revealed, and in the month of July an corporation's own inquiry found it breached the organization's journalistic standards on factual correctness.
A corporation official said: "The regulator's decision is in accordance with the conclusions of the internal assessment, that there was a major oversight in the documentary in relation to the BBC's Editorial Guidelines on factual correctness, which corresponds to Rule 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we comply with Ofcom's decision in complete. We will adhere to the sanction as soon as the schedule and wording are confirmed."
