The BBC committed a "significant breach" of broadcasting rules by failing to disclose that the voice of a film about Gaza was the child of a Hamas official, as determined by regulatory body Ofcom.
An probe by the broadcasting watchdog into Gaza: How to Survive a Warzone has found that the film was "significantly deceptive".
The head of the BBC had already issued an apology, stating there had been "a serious error in relation to factual correctness".
The authority has directed the corporation to transmit a evening declaration about its conclusions.
"Given this constitutes a major infringement of our regulations, we are ordering the broadcaster to broadcast a announcement of our conclusions against it on BBC2 at 9pm, with a schedule to be determined," the statement read.
'Potential to Erode Confidence'
The watchdog's report declared: "Our probe determined that the programme's failure to disclose that the narrator's parent served in a position in the Hamas-run authority was materially misleading.
"It meant that the public did not have critical information which may have been extremely pertinent to their judgment of the voice and the information he provided.
"Credibility is at the center of the relationship between a media organization and its public, notably for a state-funded media outlet such as the British Broadcasting Corporation.
"This oversight had the potential to undermine the significantly high levels of trust that the public would have invested in a factual film from the broadcaster about the conflict in Gaza."
The film was withdrawn from the BBC's streaming service in last February after the narrator's family links came to light, and in this past July an internal BBC review determined it breached the broadcaster's editorial guidelines on truthfulness.
A corporation official commented: "The Ofcom ruling is in agreement with the results of the corporation's inquiry, that there was a significant failing in the programme in relation to the broadcaster's journalistic policies on truthfulness, which aligns with clause 2.2 of the regulator's media standards.
"We have apologised for this and we comply with Ofcom's decision in full. We will adhere to the penalty as soon as the schedule and language are confirmed."
