The public service broadcaster engaged in a "significant breach" of media regulations by not revealing that the voice of a film about Gaza was the son of a Hamas official, according to regulatory body Ofcom.
An investigation by the media regulator into Gaza: How to Survive a Warzone has found that the film was "substantially inaccurate".
The chief executive of the broadcaster had earlier expressed regret, stating there had been "a serious error in relation to factual correctness".
The regulator has ordered the broadcaster to transmit a prime-time announcement about its findings.
"Given this constitutes a major infringement of our rules, we are instructing the corporation to transmit a message of our findings against it on BBC2 at 9pm, with a date to be finalised," the regulator stated.
'Risk to Erode Trust'
The regulator's announcement said: "Our investigation concluded that the film's omission to reveal that the voice's parent occupied a post in the Hamas-controlled administration was materially misleading.
"This implied that the public did not have critical information which may have been very significant to their judgment of the voice and the details he provided.
"Confidence is at the center of the relationship between a television network and its viewers, especially for a public service broadcaster such as the British Broadcasting Corporation.
"This oversight had the potential to undermine the significantly high levels of confidence that the public would have put in a factual film from the broadcaster about the conflict in Gaza."
The film was removed from the BBC's streaming service in last February after the narrator's family links were revealed, and in the month of July an corporation's own inquiry concluded it infringed the corporation's journalistic standards on truthfulness.
A corporation official commented: "The Ofcom ruling is in line with the findings of the internal assessment, that there was a major oversight in the programme in relation to the broadcaster's journalistic policies on truthfulness, which reflects Rule 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we comply with Ofcom's decision in full. We will adhere to the sanction as soon as the timing and wording are finalised."
