The BBC committed a "major breach" of media regulations by not revealing that the voice of a programme about the Gaza conflict was the offspring of a Hamas administrator, as ruled by UK media regulator Ofcom.
An investigation by the media regulator into Gaza: How to Survive a Warzone has determined that the programme was "substantially inaccurate".
The chief executive of the broadcaster had earlier expressed regret, saying there had been "a serious error in relation to truthfulness".
The authority has directed the BBC to transmit a peak-time declaration about its findings.
"As this represents a significant violation of our rules, we are instructing the broadcaster to air a statement of our findings against it on BBC2 at 21:00, with a timing to be confirmed," it said.
'Potential to Damage Trust'
The regulator's announcement said: "The inquiry we conducted concluded that the programme's failure to disclose that the voice's male guardian occupied a post in the Hamas-controlled government was substantially inaccurate.
"This implied that the public did not have vital facts which may have been very significant to their assessment of the presenter and the content he provided.
"Confidence is at the core of the relationship between a television network and its public, notably for a public service broadcaster such as the British Broadcasting Corporation.
"This failing had the possibility to damage the exceptionally strong degrees of credibility that viewers would have invested in a BBC factual programme about the conflict in Gaza."
The film was pulled from the online platform in last February after the presenter's family links were revealed, and in this past July an broadcaster's internal assessment concluded it infringed the broadcaster's journalistic standards on accuracy.
A BBC spokesperson stated: "The regulator's decision is in line with the results of the corporation's inquiry, that there was a significant failing in the film in relation to the broadcaster's journalistic policies on accuracy, which corresponds to regulation 2.2 of the authority's broadcasting regulations.
"We have apologised for this and we comply with Ofcom's decision in full. We will follow the sanction as soon as the date and wording are determined."
