The public service broadcaster committed a "serious breach" of industry standards by omitting to mention that the narrator of a film about the Gaza conflict was the child of a Hamas administrator, as determined by UK media regulator Ofcom.
An inquiry by the media regulator into the programme Gaza: How to Survive a Warzone has concluded that the film was "significantly deceptive".
The BBC's director general had previously apologised, saying there had been "a serious error in relation to factual correctness".
Ofcom has instructed the BBC to air a peak-time declaration about its conclusions.
"Since this amounts to a major infringement of our regulations, we are ordering the BBC to transmit a message of our findings against it on BBC2 at nine o'clock in the evening, with a timing to be confirmed," the regulator stated.
'Potential to Erode Credibility'
The regulator's announcement said: "The inquiry we conducted concluded that the documentary's lack of disclosure that the voice's father served in a role in the Hamas-controlled administration was materially misleading.
"Consequently that the public did not have critical information which may have been extremely pertinent to their judgment of the narrator and the details he presented.
"Confidence is at the heart of the relationship between a television network and its viewers, especially for a public service broadcaster such as the BBC.
"This error had the risk to erode the exceptionally strong levels of confidence that the public would have put in a factual film from the broadcaster about the conflict in Gaza."
The documentary was removed from the BBC's streaming service in February after the presenter's family links were revealed, and in this past July an broadcaster's internal assessment determined it infringed the corporation's content policies on truthfulness.
A representative for the broadcaster commented: "The regulator's decision is in accordance with the findings of the internal assessment, that there was a significant failing in the programme in relation to the broadcaster's journalistic policies on truthfulness, which reflects clause 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we accept Ofcom's decision in full. We will comply with the sanction as soon as the date and wording are finalised."
