The British broadcaster was found to have committed a "serious breach" of media regulations by not revealing that the narrator of a film about the Gaza situation was the child of a Hamas representative, according to regulatory body Ofcom.
An investigation by the media regulator into Gaza: How to Survive a Warzone has concluded that the documentary was "substantially inaccurate".
The BBC's director general had already issued an apology, noting there had been "a significant failing in relation to truthfulness".
The regulator has ordered the broadcaster to broadcast a evening declaration about its findings.
"As this represents a significant violation of our code, we are ordering the corporation to air a announcement of our determinations against it on the BBC's second channel at 21:00, with a schedule to be finalised," it said.
'Possibility to Erode Credibility'
The authority's report said: "Our probe concluded that the programme's omission to reveal that the narrator's father held a role in the Hamas-administered authority was significantly deceptive.
"This implied that the audience did not have critical information which may have been extremely pertinent to their evaluation of the presenter and the information he shared.
"Trust is at the center of the relationship between a media organization and its viewers, especially for a national broadcasting corporation such as the public broadcaster.
"This oversight had the risk to damage the very considerable degrees of trust that the public would have invested in a BBC factual programme about the conflict in Gaza."
The programme was pulled from the BBC's streaming service in last February after the boy's familial connections were revealed, and in July an internal BBC review found it breached the corporation's content policies on factual correctness.
A corporation official said: "The authority's determination is in accordance with the findings of the corporation's inquiry, that there was a major oversight in the documentary in relation to the corporation's content standards on accuracy, which reflects Rule 2.2 of the authority's broadcasting regulations.
"We have apologised for this and we agree with Ofcom's decision in full. We will follow the penalty as soon as the timing and wording are determined."
