The BBC engaged in a "major breach" of broadcasting rules by failing to disclose that the narrator of a documentary about Gaza was the child of a Hamas representative, as determined by regulatory body Ofcom.
An probe by the media regulator into Gaza: How to Survive a Warzone has concluded that the programme was "materially misleading".
The head of the BBC had earlier expressed regret, stating there had been "a serious error in relation to factual correctness".
The regulator has instructed the BBC to transmit a evening announcement about its conclusions.
"As this represents a significant violation of our code, we are directing the BBC to transmit a statement of our findings against it on the BBC's second channel at 9pm, with a date to be confirmed," the statement read.
'Potential to Undermine Trust'
The authority's report declared: "Our investigation concluded that the film's failure to disclose that the voice's father occupied a role in the Hamas-controlled administration was significantly deceptive.
"Consequently that the public did not have critical information which may have been very significant to their evaluation of the narrator and the details he presented.
"Trust is at the core of the relationship between a media organization and its public, notably for a national broadcasting corporation such as the BBC.
"This failing had the potential to damage the significantly high degrees of credibility that the public would have invested in a BBC factual programme about the Gaza conflict."
The film was pulled from the BBC's streaming service in last February after the presenter's family links emerged, and in the month of July an internal BBC review found it breached the corporation's content policies on accuracy.
A BBC spokesperson stated: "The authority's determination is in accordance with the findings of the internal assessment, that there was a significant failing in the documentary in relation to the BBC's Editorial Guidelines on accuracy, which reflects regulation 2.2 of the regulator's media standards.
"We issued an apology for this and we comply with the regulator's ruling in full. We will adhere to the penalty as soon as the date and language are finalised."
