The BBC engaged in a "significant breach" of broadcasting rules by failing to disclose that the voice of a programme about the Gaza situation was the son of a Hamas official, according to British broadcasting authority Ofcom.
An probe by the broadcasting watchdog into the programme Gaza: How to Survive a Warzone has determined that the film was "materially misleading".
The BBC's director general had earlier expressed regret, noting there had been "a serious error in relation to accuracy".
The regulator has directed the corporation to air a prime-time announcement about its conclusions.
"Given this constitutes a serious breach of our regulations, we are directing the broadcaster to transmit a announcement of our determinations against it on BBC2 at 9pm, with a timing to be confirmed," the regulator stated.
'Risk to Undermine Trust'
The watchdog's announcement declared: "Our probe found that the documentary's failure to disclose that the presenter's male guardian served in a role in the Hamas-administered government was significantly deceptive.
"It meant that the audience did not have critical information which may have been highly relevant to their evaluation of the voice and the details he shared.
"Trust is at the heart of the relationship between a media organization and its viewers, particularly for a national broadcasting corporation such as the BBC.
"This failing had the possibility to damage the exceptionally strong levels of confidence that audiences would have placed in a documentary produced by the BBC about the Gaza conflict."
The programme was removed from the online platform in last February after the narrator's familial connections were revealed, and in the month of July an broadcaster's internal assessment concluded it infringed the broadcaster's journalistic standards on accuracy.
A corporation official said: "The Ofcom ruling is in accordance with the results of the corporation's inquiry, that there was a significant failing in the film in relation to the corporation's content standards on truthfulness, which reflects regulation 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we accept Ofcom's decision in its entirety. We will follow the penalty as soon as the date and wording are determined."
