The public service broadcaster committed a "significant breach" of industry standards by not revealing that the narrator of a film about Gaza was the child of a Hamas representative, as determined by UK media regulator Ofcom.
An inquiry by the media regulator into Gaza: How to Survive a Warzone has found that the film was "materially misleading".
The head of the BBC had previously apologised, noting there had been "a significant failing in relation to accuracy".
The authority has instructed the BBC to broadcast a prime-time statement about its findings.
"As this represents a serious breach of our code, we are ordering the broadcaster to transmit a announcement of our conclusions against it on the BBC's second channel at nine o'clock in the evening, with a date to be finalised," the regulator stated.
'Potential to Undermine Trust'
The watchdog's report declared: "Our probe concluded that the film's failure to disclose that the voice's parent held a post in the Hamas-administered authority was substantially inaccurate.
"It meant that the viewers did not have vital facts which may have been extremely pertinent to their judgment of the presenter and the details he provided.
"Confidence is at the heart of the relationship between a media organization and its viewers, especially for a national broadcasting corporation such as the BBC.
"This error had the potential to damage the very considerable amounts of confidence that the public would have put in a factual film from the broadcaster about the conflict in Gaza."
The programme was withdrawn from iPlayer in the month of February after the narrator's familial connections came to light, and in July an broadcaster's internal assessment found it infringed the broadcaster's editorial guidelines on accuracy.
A BBC spokesperson said: "The regulator's decision is in agreement with the results of the corporation's inquiry, that there was a significant failing in the documentary in relation to the corporation's content standards on accuracy, which aligns with Rule 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we agree with the authority's determination in its entirety. We will adhere to the sanction as soon as the timing and wording are determined."
