The BBC committed a "serious breach" of media regulations by omitting to mention that the narrator of a programme about the Gaza situation was the offspring of a Hamas administrator, according to British broadcasting authority Ofcom.
An investigation by the broadcasting watchdog into Gaza: How to Survive a Warzone has concluded that the programme was "materially misleading".
The head of the BBC had already issued an apology, noting there had been "a significant failing in relation to accuracy".
Ofcom has ordered the broadcaster to air a peak-time declaration about its decisions.
"Given this constitutes a significant violation of our code, we are instructing the corporation to broadcast a message of our determinations against it on BBC2 at 9pm, with a schedule to be determined," it said.
'Risk to Erode Trust'
The regulator's statement declared: "The inquiry we conducted found that the film's lack of disclosure that the voice's parent served in a role in the Hamas-administered government was materially misleading.
"It meant that the audience did not have vital facts which may have been extremely pertinent to their judgment of the presenter and the details he shared.
"Confidence is at the heart of the bond between a television network and its public, notably for a public service broadcaster such as the BBC.
"This error had the risk to damage the exceptionally strong levels of confidence that viewers would have invested in a documentary produced by the BBC about the Gaza conflict."
The documentary was removed from iPlayer in February after the presenter's family links came to light, and in this past July an broadcaster's internal assessment found it violated the broadcaster's editorial guidelines on factual correctness.
A BBC spokesperson commented: "The Ofcom ruling is in line with the findings of the corporation's inquiry, that there was a major oversight in the film in relation to the broadcaster's journalistic policies on accuracy, which corresponds to regulation 2.2 of the regulator's media standards.
"We expressed regret for this and we agree with the regulator's ruling in its entirety. We will follow the directive as soon as the timing and wording are finalised."
