The BBC engaged in a "serious breach" of media regulations by not revealing that the narrator of a programme about the Gaza conflict was the son of a Hamas administrator, according to regulatory body Ofcom.
An probe by the broadcasting watchdog into Gaza: How to Survive a Warzone has concluded that the film was "significantly deceptive".
The chief executive of the broadcaster had previously apologised, stating there had been "a significant failing in relation to factual correctness".
Ofcom has ordered the corporation to transmit a peak-time declaration about its findings.
"As this represents a major infringement of our code, we are instructing the BBC to transmit a message of our findings against it on the BBC's second channel at 21:00, with a date to be finalised," the statement read.
'Possibility to Damage Trust'
The regulator's statement said: "Our investigation found that the film's omission to reveal that the voice's father occupied a role in the Hamas-controlled authority was materially misleading.
"This implied that the viewers did not have essential details which may have been highly relevant to their assessment of the narrator and the information he presented.
"Trust is at the core of the bond between a media organization and its audience, notably for a national broadcasting corporation such as the BBC.
"This failing had the risk to damage the very considerable degrees of confidence that audiences would have put in a BBC factual programme about the Israel-Gaza war."
The documentary was withdrawn from iPlayer in last February after the presenter's familial connections were revealed, and in July an internal BBC review found it breached the broadcaster's content policies on factual correctness.
A corporation official said: "The Ofcom ruling is in agreement with the conclusions of the internal assessment, that there was a serious error in the film in relation to the broadcaster's journalistic policies on factual correctness, which reflects clause 2.2 of the regulator's media standards.
"We expressed regret for this and we accept the authority's determination in full. We will adhere to the directive as soon as the date and wording are finalised."
