The British broadcaster engaged in a "major breach" of broadcasting rules by not revealing that the voice of a film about Gaza was the child of a Hamas representative, as ruled by UK media regulator Ofcom.
An probe by the media regulator into Gaza: How to Survive a Warzone has found that the documentary was "substantially inaccurate".
The BBC's director general had already issued an apology, saying there had been "a major oversight in relation to truthfulness".
The authority has directed the corporation to transmit a prime-time declaration about its findings.
"As this represents a major infringement of our code, we are directing the BBC to transmit a statement of our findings against it on BBC2 at 21:00, with a date to be finalised," it said.
'Risk to Undermine Credibility'
The regulator's announcement declared: "The inquiry we conducted concluded that the programme's lack of disclosure that the presenter's male guardian occupied a post in the Hamas-controlled government was materially misleading.
"It meant that the viewers did not have essential details which may have been extremely pertinent to their assessment of the voice and the content he provided.
"Credibility is at the center of the connection between a media organization and its viewers, particularly for a public service broadcaster such as the British Broadcasting Corporation.
"This error had the risk to erode the exceptionally strong levels of trust that audiences would have invested in a documentary produced by the BBC about the Israel-Gaza war."
The documentary was removed from iPlayer in February after the presenter's family links emerged, and in the month of July an broadcaster's internal assessment concluded it breached the organization's journalistic standards on truthfulness.
A BBC spokesperson said: "The authority's determination is in agreement with the results of the corporation's inquiry, that there was a serious error in the programme in relation to the broadcaster's journalistic policies on truthfulness, which reflects regulation 2.2 of the authority's broadcasting regulations.
"We have apologised for this and we accept the authority's determination in complete. We will comply with the directive as soon as the timing and language are finalised."
