The public service broadcaster engaged in a "significant breach" of industry standards by failing to disclose that the presenter of a film about the Gaza conflict was the child of a Hamas official, according to UK media regulator Ofcom.
An inquiry by the media regulator into Gaza: How to Survive a Warzone has determined that the programme was "substantially inaccurate".
The chief executive of the broadcaster had already issued an apology, saying there had been "a significant failing in relation to factual correctness".
The regulator has instructed the broadcaster to transmit a prime-time statement about its findings.
"As this represents a serious breach of our rules, we are directing the BBC to air a message of our determinations against it on the BBC's second channel at nine o'clock in the evening, with a timing to be confirmed," the statement read.
'Risk to Erode Confidence'
The authority's report declared: "Our probe found that the programme's failure to disclose that the voice's parent occupied a post in the Hamas-administered administration was significantly deceptive.
"This implied that the audience did not have critical information which may have been very significant to their assessment of the presenter and the details he provided.
"Trust is at the core of the bond between a broadcaster and its audience, particularly for a state-funded media outlet such as the BBC.
"This error had the potential to damage the exceptionally strong amounts of credibility that audiences would have placed in a documentary produced by the BBC about the Gaza conflict."
The programme was removed from the online platform in last February after the presenter's personal associations were revealed, and in July an internal BBC review determined it violated the corporation's journalistic standards on accuracy.
A representative for the broadcaster commented: "The Ofcom ruling is in line with the findings of the corporation's inquiry, that there was a serious error in the film in relation to the BBC's Editorial Guidelines on accuracy, which corresponds to regulation 2.2 of the authority's broadcasting regulations.
"We have apologised for this and we agree with Ofcom's decision in its entirety. We will adhere to the sanction as soon as the timing and language are confirmed."
