The public service broadcaster was found to have committed a "major breach" of industry standards by not revealing that the voice of a documentary about the Gaza conflict was the offspring of a Hamas official, as determined by British broadcasting authority Ofcom.
An probe by Ofcom into the programme Gaza: How to Survive a Warzone has found that the documentary was "substantially inaccurate".
The head of the BBC had already issued an apology, noting there had been "a serious error in relation to accuracy".
The regulator has ordered the BBC to air a evening statement about its conclusions.
"As this represents a serious breach of our code, we are directing the corporation to broadcast a message of our findings against it on BBC Two at 21:00, with a date to be determined," the regulator stated.
'Risk to Damage Trust'
The watchdog's announcement stated: "Our investigation found that the documentary's failure to disclose that the presenter's male guardian occupied a position in the Hamas-controlled authority was substantially inaccurate.
"This implied that the viewers did not have essential details which may have been very significant to their evaluation of the narrator and the information he presented.
"Credibility is at the heart of the connection between a media organization and its audience, notably for a public service broadcaster such as the British Broadcasting Corporation.
"This oversight had the risk to damage the very considerable amounts of confidence that audiences would have placed in a BBC factual programme about the Israel-Gaza war."
The documentary was withdrawn from the BBC's streaming service in February after the presenter's family links were revealed, and in this past July an internal BBC review found it infringed the broadcaster's editorial guidelines on factual correctness.
A BBC spokesperson said: "The authority's determination is in accordance with the findings of the corporation's inquiry, that there was a major oversight in the film in relation to the BBC's Editorial Guidelines on accuracy, which corresponds to Rule 2.2 of the authority's broadcasting regulations.
"We have apologised for this and we accept Ofcom's decision in complete. We will follow the directive as soon as the timing and language are finalised."
