The public service broadcaster committed a "significant breach" of media regulations by not revealing that the narrator of a programme about the Gaza conflict was the child of a Hamas official, according to regulatory body Ofcom.
An investigation by the broadcasting watchdog into the programme Gaza: How to Survive a Warzone has concluded that the programme was "materially misleading".
The BBC's director general had previously apologised, stating there had been "a significant failing in relation to accuracy".
The authority has ordered the BBC to broadcast a peak-time announcement about its decisions.
"Given this constitutes a significant violation of our regulations, we are directing the corporation to transmit a announcement of our conclusions against it on the BBC's second channel at nine o'clock in the evening, with a schedule to be finalised," the regulator stated.
'Possibility to Erode Confidence'
The authority's statement said: "Our probe concluded that the programme's omission to reveal that the voice's father served in a role in the Hamas-administered authority was significantly deceptive.
"It meant that the viewers did not have essential details which may have been extremely pertinent to their judgment of the narrator and the content he shared.
"Credibility is at the core of the bond between a television network and its audience, notably for a public service broadcaster such as the British Broadcasting Corporation.
"This oversight had the potential to erode the exceptionally strong degrees of confidence that the public would have placed in a BBC factual programme about the conflict in Gaza."
The programme was removed from the BBC's streaming service in the month of February after the presenter's family links were revealed, and in July an internal BBC review found it violated the broadcaster's journalistic standards on accuracy.
A BBC spokesperson said: "The regulator's decision is in accordance with the conclusions of the internal assessment, that there was a major oversight in the documentary in relation to the BBC's Editorial Guidelines on factual correctness, which reflects Rule 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we agree with Ofcom's decision in complete. We will adhere to the sanction as soon as the date and wording are determined."
