The British broadcaster committed a "major breach" of industry standards by omitting to mention that the voice of a film about Gaza was the son of a Hamas official, according to regulatory body Ofcom.
An inquiry by Ofcom into Gaza: How to Survive a Warzone has concluded that the film was "substantially inaccurate".
The head of the BBC had already issued an apology, noting there had been "a major oversight in relation to truthfulness".
The regulator has ordered the BBC to air a prime-time announcement about its decisions.
"As this represents a serious breach of our rules, we are ordering the broadcaster to air a message of our determinations against it on the BBC's second channel at 21:00, with a schedule to be finalised," it said.
'Risk to Erode Credibility'
The watchdog's announcement said: "Our probe concluded that the documentary's lack of disclosure that the presenter's male guardian occupied a role in the Hamas-run authority was significantly deceptive.
"Consequently that the audience did not have essential details which may have been very significant to their judgment of the narrator and the details he shared.
"Credibility is at the core of the bond between a media organization and its audience, particularly for a national broadcasting corporation such as the BBC.
"This failing had the risk to damage the exceptionally strong levels of trust that the public would have put in a factual film from the broadcaster about the Israel-Gaza war."
The documentary was removed from the BBC's streaming service in the month of February after the boy's family links came to light, and in the month of July an corporation's own inquiry determined it violated the broadcaster's editorial guidelines on truthfulness.
A representative for the broadcaster said: "The regulator's decision is in agreement with the conclusions of Peter Johnston's review, 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 the authority's broadcasting regulations.
"We issued an apology for this and we comply with the regulator's ruling in its entirety. We will comply with the directive as soon as the schedule and language are finalised."
