The public service broadcaster engaged in a "serious breach" of broadcasting rules by omitting to mention that the voice of a film about Gaza was the child of a Hamas representative, as determined by British broadcasting authority Ofcom.
An probe by the media regulator into the programme Gaza: How to Survive a Warzone has determined 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 accuracy".
Ofcom has ordered the corporation to air a evening announcement about its findings.
"Given this constitutes a major infringement of our code, we are directing the corporation to broadcast a message of our conclusions against it on BBC Two at nine o'clock in the evening, with a schedule to be determined," it said.
'Possibility to Damage Confidence'
The watchdog's announcement said: "Our investigation found that the film's lack of disclosure that the narrator's parent served in a post in the Hamas-run government was materially misleading.
"It meant that the audience did not have critical information which may have been extremely pertinent to their evaluation of the voice and the content he provided.
"Credibility is at the center of the relationship between a television network and its viewers, particularly for a national broadcasting corporation such as the public broadcaster.
"This error had the possibility to damage the exceptionally strong amounts of trust that audiences would have put in a BBC factual programme about the conflict in Gaza."
The documentary was withdrawn from the BBC's streaming service in the month of February after the presenter's family links emerged, and in the month of July an internal BBC review determined it breached the corporation's content policies on accuracy.
A representative for the broadcaster commented: "The authority's determination is in line with the results of the corporation's inquiry, that there was a major oversight in the programme in relation to the corporation's content standards on truthfulness, which reflects regulation 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we agree with the authority's determination in its entirety. We will comply with the sanction as soon as the schedule and wording are finalised."
