The public service broadcaster engaged in a "major breach" of broadcasting rules by not revealing that the narrator of a documentary about the Gaza conflict was the child of a Hamas official, as ruled by British broadcasting authority Ofcom.
An investigation by Ofcom into Gaza: How to Survive a Warzone has concluded that the film was "materially misleading".
The head of the BBC had earlier expressed regret, saying there had been "a serious error in relation to accuracy".
The regulator has ordered the broadcaster to air a evening statement about its decisions.
"Since this amounts to a significant violation of our code, we are ordering the corporation to air a message of our findings against it on BBC Two at 9pm, with a date to be finalised," it said.
'Risk to Undermine Credibility'
The authority's report declared: "Our probe found that the film's omission to reveal that the presenter's parent served in a post in the Hamas-run authority was substantially inaccurate.
"This implied that the public did not have essential details which may have been extremely pertinent to their evaluation of the narrator and the details he provided.
"Credibility is at the heart of the relationship between a television network and its public, particularly for a state-funded media outlet such as the public broadcaster.
"This error had the possibility to undermine the exceptionally strong levels of credibility that the public would have invested in a BBC factual programme about the Israel-Gaza war."
The documentary was pulled from iPlayer in the month of February after the boy's familial connections came to light, and in this past July an corporation's own inquiry determined it violated the broadcaster's editorial guidelines on accuracy.
A BBC spokesperson said: "The authority's determination is in accordance with the findings of the corporation's inquiry, that there was a significant failing in the film in relation to the corporation's content standards on accuracy, which aligns with clause 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we comply with Ofcom's decision in full. We will follow the sanction as soon as the date and wording are confirmed."
