The public service broadcaster engaged in a "serious breach" of broadcasting rules by not revealing that the voice of a film about the Gaza situation was the child of a Hamas administrator, according to UK media regulator Ofcom.
An inquiry by Ofcom into the programme Gaza: How to Survive a Warzone has determined that the film was "substantially inaccurate".
The BBC's director general had already issued an apology, stating there had been "a major oversight in relation to accuracy".
The authority has ordered the corporation to broadcast a evening announcement about its conclusions.
"As this represents a major infringement of our code, we are directing the corporation to transmit a message of our determinations against it on the BBC's second channel at nine o'clock in the evening, with a date to be finalised," the statement read.
'Potential to Damage Credibility'
The regulator's announcement declared: "The inquiry we conducted found that the documentary's omission to reveal that the voice's father served in a post in the Hamas-controlled administration was substantially inaccurate.
"Consequently that the viewers did not have essential details which may have been extremely pertinent to their evaluation of the presenter and the information he provided.
"Confidence is at the heart of the connection between a television network and its audience, especially for a national broadcasting corporation such as the BBC.
"This error had the potential to damage the exceptionally strong levels of trust that audiences would have placed 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The documentary was withdrawn from the BBC's streaming service in the month of February after the presenter's familial connections were revealed, and in July an corporation's own inquiry concluded it breached the broadcaster's content policies on accuracy.
A corporation official commented: "The authority's determination is in line with the results of the internal assessment, that there was a serious error in the film in relation to the corporation's content standards on factual correctness, which reflects regulation 2.2 of the authority's broadcasting regulations.
"We have apologised for this and we accept the authority's determination in full. We will follow the sanction as soon as the timing and wording are confirmed."
