The public service broadcaster committed a "significant breach" of industry standards by failing to disclose that the voice of a documentary about the Gaza situation was the child of a Hamas representative, according to British broadcasting authority Ofcom.
An inquiry by Ofcom into the programme Gaza: How to Survive a Warzone has found that the documentary was "significantly deceptive".
The head of the BBC had already issued an apology, saying there had been "a major oversight in relation to accuracy".
The regulator has directed the broadcaster to air a prime-time announcement about its decisions.
"Since this amounts to a significant violation of our code, we are instructing the BBC to broadcast a announcement of our findings against it on BBC2 at 21:00, with a timing to be determined," it said.
'Potential to Erode Confidence'
The regulator's statement said: "Our probe determined that the programme's lack of disclosure that the presenter's male guardian held a post in the Hamas-run administration was significantly deceptive.
"This implied that the audience did not have critical information which may have been very significant to their assessment of the narrator and the content he provided.
"Confidence is at the center of the relationship between a broadcaster and its viewers, especially for a public service broadcaster such as the public broadcaster.
"This failing had the risk to erode the significantly high amounts of trust that the public would have placed in a BBC factual programme about the conflict in Gaza."
The documentary was pulled from the online platform in February after the boy's family links were revealed, and in July an broadcaster's internal assessment found it infringed the organization's journalistic standards on accuracy.
A BBC spokesperson stated: "The regulator's decision is in accordance with the findings of the corporation's inquiry, that there was a serious error in the film in relation to the corporation's content standards on factual correctness, which reflects clause 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we comply with Ofcom's decision in its entirety. We will comply with the sanction as soon as the date and wording are finalised."
