The public service broadcaster engaged in a "major breach" of broadcasting rules by failing to disclose that the voice of a film about Gaza was the son of a Hamas official, according to UK media regulator Ofcom.
An investigation by the broadcasting watchdog into Gaza: How to Survive a Warzone has concluded that the programme was "materially misleading".
The head of the BBC had already issued an apology, saying there had been "a major oversight in relation to accuracy".
Ofcom has ordered the BBC to air a evening statement about its conclusions.
"As this represents a serious breach of our regulations, we are ordering the broadcaster to air a announcement of our findings against it on BBC Two at 9pm, with a schedule to be confirmed," it said.
'Risk to Damage Trust'
The regulator's statement stated: "The inquiry we conducted determined that the documentary's omission to reveal that the narrator's parent served in a position in the Hamas-controlled administration was substantially inaccurate.
"This implied that the audience did not have vital facts which may have been highly relevant to their judgment of the presenter and the content he shared.
"Trust is at the center of the connection between a television network and its public, notably for a public service broadcaster such as the BBC.
"This oversight had the potential to damage the significantly high amounts of credibility that viewers would have placed in a BBC factual programme about the conflict in Gaza."
The programme was pulled from the online platform in February after the narrator's family links were revealed, and in the month of July an internal BBC review concluded it violated the broadcaster's editorial guidelines on accuracy.
A corporation official said: "The regulator's decision is in line with the findings of Peter Johnston's review, that there was a major oversight in the documentary in relation to the broadcaster's journalistic policies on factual correctness, which corresponds to Rule 2.2 of the regulator's media standards.
"We issued an apology for this and we comply with Ofcom's decision in its entirety. We will comply with the directive as soon as the date and wording are confirmed."
