The BBC committed a "major breach" of broadcasting rules by omitting to mention that the voice of a film about Gaza was the offspring of a Hamas representative, according to UK media regulator Ofcom.
An inquiry by the broadcasting watchdog into the programme Gaza: How to Survive a Warzone has concluded that the programme was "significantly deceptive".
The BBC's director general had earlier expressed regret, stating there had been "a serious error in relation to accuracy".
The regulator has ordered the BBC to broadcast a peak-time announcement about its findings.
"Given this constitutes a major infringement of our regulations, we are directing the BBC to transmit a message of our findings against it on BBC Two at 9pm, with a date to be confirmed," the regulator stated.
'Potential to Erode Trust'
The authority's statement said: "Our probe found that the documentary's omission to reveal that the narrator's male guardian occupied a role in the Hamas-administered government was materially misleading.
"This implied that the viewers did not have vital facts which may have been highly relevant to their evaluation of the voice and the details he provided.
"Trust is at the core of the relationship between a television network and its audience, notably for a national broadcasting corporation such as the BBC.
"This failing had the potential to erode the significantly high degrees of credibility that viewers would have placed in a factual film from the broadcaster about the Israel-Gaza war."
The programme was pulled from iPlayer in February after the narrator's personal associations came to light, and in the month of July an broadcaster's internal assessment concluded it infringed the corporation's editorial guidelines on truthfulness.
A representative for the broadcaster commented: "The Ofcom ruling is in accordance with the results of the internal assessment, that there was a serious error in the film in relation to the corporation's content standards on truthfulness, which aligns with clause 2.2 of the regulator's media standards.
"We issued an apology for this and we comply with the authority's determination in full. We will adhere to the directive as soon as the timing and wording are finalised."
