The BBC was found to have committed 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 inquiry by Ofcom into Gaza: How to Survive a Warzone has found that the film was "substantially inaccurate".
The BBC's director general had earlier expressed regret, stating there had been "a serious error in relation to truthfulness".
The authority has directed the BBC to air a prime-time announcement about its decisions.
"As this represents a major infringement of our code, we are instructing the corporation to air a announcement of our findings against it on BBC2 at nine o'clock in the evening, with a timing to be confirmed," the regulator stated.
'Potential to Undermine Confidence'
The regulator's statement declared: "The inquiry we conducted determined that the film's omission to reveal that the voice's father served in a role in the Hamas-controlled authority was materially misleading.
"This implied that the viewers did not have vital facts which may have been extremely pertinent to their judgment of the presenter and the content he provided.
"Confidence is at the center of the relationship between a media organization and its viewers, particularly for a state-funded media outlet such as the BBC.
"This failing had the potential to undermine the very considerable degrees of credibility that the public would have put in a BBC factual programme about the Israel-Gaza war."
The programme was withdrawn from the BBC's streaming service in the month of February after the narrator's familial connections emerged, and in the month of July an internal BBC review concluded it violated the organization's content policies on factual correctness.
A representative for the broadcaster commented: "The regulator's decision is in accordance with the findings of the internal assessment, that there was a serious error in the programme in relation to the corporation's content standards on factual correctness, which reflects Rule 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we accept the authority's determination in its entirety. We will comply with the penalty as soon as the timing and wording are finalised."
