The public service broadcaster engaged in a "major breach" of broadcasting rules by not revealing that the voice of a programme about Gaza was the offspring of a Hamas representative, as ruled by British broadcasting authority Ofcom.
An investigation by Ofcom into Gaza: How to Survive a Warzone has determined that the programme was "substantially inaccurate".
The head of the BBC had earlier expressed regret, noting there had been "a major oversight in relation to factual correctness".
The authority has ordered the corporation to air a evening announcement about its findings.
"As this represents a significant violation of our rules, we are ordering the corporation to broadcast a message of our determinations against it on the BBC's second channel at nine o'clock in the evening, with a schedule to be determined," it said.
'Potential to Undermine Credibility'
The authority's statement declared: "The inquiry we conducted concluded that the programme's failure to disclose that the presenter's father served in a position in the Hamas-controlled administration was materially misleading.
"This implied that the viewers did not have critical information which may have been highly relevant to their assessment of the presenter and the details he presented.
"Trust is at the center of the connection between a television network and its viewers, notably for a national broadcasting corporation such as the British Broadcasting Corporation.
"This error had the risk to damage the significantly high levels of trust that audiences would have invested in a factual film from the broadcaster about the conflict in Gaza."
The film was pulled from the BBC's streaming service in last February after the narrator's personal associations emerged, and in this past July an corporation's own inquiry found it breached the organization's content policies on accuracy.
A BBC spokesperson commented: "The authority's determination is in accordance with the conclusions of the corporation's inquiry, that there was a serious error in the film in relation to the broadcaster's journalistic policies on accuracy, which aligns with clause 2.2 of the regulator's media standards.
"We have apologised for this and we agree with the regulator's ruling in complete. We will follow the sanction as soon as the timing and wording are determined."
