The BBC engaged in a "significant breach" of media regulations by not revealing that the presenter of a documentary about Gaza was the son of a Hamas administrator, according to regulatory body Ofcom.
An inquiry by the media regulator into Gaza: How to Survive a Warzone has concluded that the programme was "significantly deceptive".
The chief executive of the broadcaster had earlier expressed regret, noting there had been "a serious error in relation to factual correctness".
The authority has ordered the BBC to transmit a prime-time declaration about its decisions.
"Since this amounts to a significant violation of our code, we are instructing the corporation to broadcast a announcement of our conclusions against it on BBC2 at 9pm, with a date to be finalised," the regulator stated.
'Potential to Erode Confidence'
The watchdog's statement stated: "Our investigation concluded that the documentary's lack of disclosure that the narrator's father occupied a post in the Hamas-administered government was substantially inaccurate.
"It meant that the public did not have essential details which may have been extremely pertinent to their assessment of the voice and the details he presented.
"Trust is at the core of the connection between a broadcaster and its public, especially for a state-funded media outlet such as the British Broadcasting Corporation.
"This failing had the possibility to damage the significantly high amounts of confidence that viewers would have put in a factual film from the broadcaster about the Israel-Gaza war."
The programme was pulled from iPlayer in February after the boy's family links emerged, and in the month of July an corporation's own inquiry found it violated the corporation's content policies on accuracy.
A BBC spokesperson commented: "The regulator's decision is in accordance with the findings of the corporation's inquiry, that there was a serious error in the film in relation to the corporation's content standards on accuracy, which reflects Rule 2.2 of the regulator's media standards.
"We have apologised for this and we comply with the authority's determination in full. We will adhere to the sanction as soon as the timing and wording are determined."
