The public service broadcaster committed a "significant breach" of industry standards by not revealing that the voice of a programme about the Gaza situation was the offspring of a Hamas representative, as ruled by British broadcasting authority Ofcom.
An inquiry by the media regulator into the programme Gaza: How to Survive a Warzone has determined that the programme was "significantly deceptive".
The head of the BBC had already issued an apology, noting there had been "a significant failing in relation to truthfulness".
The regulator has instructed the BBC to air a evening declaration about its conclusions.
"Since this amounts to a serious breach of our code, we are directing the BBC to broadcast a announcement of our findings against it on the BBC's second channel at nine o'clock in the evening, with a schedule to be confirmed," it said.
'Risk to Erode Trust'
The authority's statement said: "The inquiry we conducted determined that the programme's lack of disclosure that the presenter's parent held a role in the Hamas-run administration was significantly deceptive.
"This implied that the public did not have essential details which may have been highly relevant to their assessment of the voice and the content he shared.
"Confidence is at the center of the bond between a media organization and its audience, notably for a national broadcasting corporation such as the BBC.
"This failing had the possibility to erode the significantly high amounts of credibility that viewers would have put in a BBC factual programme about the conflict in Gaza."
The film was removed from iPlayer in February after the narrator's family links emerged, and in the month of July an broadcaster's internal assessment found it breached the corporation's content policies on accuracy.
A corporation official commented: "The Ofcom ruling is in agreement with the results of the internal assessment, that there was a significant failing in the documentary in relation to the corporation's content standards on factual correctness, which aligns with clause 2.2 of the regulator's media standards.
"We have apologised for this and we accept the authority's determination in complete. We will adhere to the sanction as soon as the schedule and wording are finalised."
