The BBC committed a "significant breach" of industry standards by not revealing that the presenter of a film about the Gaza situation was the offspring of a Hamas official, as determined by regulatory body Ofcom.
An probe by the media regulator into Gaza: How to Survive a Warzone has found that the programme was "substantially inaccurate".
The head of the BBC had already issued an apology, noting there had been "a serious error in relation to factual correctness".
The regulator has ordered the broadcaster to air a peak-time statement about its conclusions.
"As this represents a significant violation of our code, we are instructing the BBC to air a statement of our determinations against it on the BBC's second channel at 21:00, with a date to be determined," it said.
'Potential to Damage Confidence'
The regulator's announcement stated: "Our investigation concluded that the programme's omission to reveal that the narrator's parent served in a post in the Hamas-controlled administration was significantly deceptive.
"It meant that the audience did not have vital facts which may have been extremely pertinent to their evaluation of the voice and the content he shared.
"Trust is at the heart of the relationship between a media organization and its public, particularly for a national broadcasting corporation such as the British Broadcasting Corporation.
"This oversight had the risk to erode the significantly high levels of confidence that audiences would have put in a BBC factual programme about the Gaza conflict."
The film was withdrawn from the BBC's streaming service in the month of February after the presenter's familial connections were revealed, and in this past July an broadcaster's internal assessment determined it breached the corporation's journalistic standards on factual correctness.
A BBC spokesperson said: "The regulator's decision is in line with the findings of Peter Johnston's review, that there was a significant failing in the film in relation to the corporation's content standards on accuracy, which corresponds to Rule 2.2 of the regulator's media standards.
"We issued an apology for this and we accept the authority's determination in full. We will adhere to the sanction as soon as the schedule and wording are determined."
