The BBC committed a "major breach" of industry standards by omitting to mention that the presenter of a programme about the Gaza situation was the offspring of a Hamas representative, as determined by British broadcasting authority Ofcom.
An inquiry by the media regulator into the programme Gaza: How to Survive a Warzone has determined that the documentary was "substantially inaccurate".
The BBC's director general had already issued an apology, saying there had been "a serious error in relation to accuracy".
Ofcom has ordered the broadcaster to transmit a peak-time statement about its decisions.
"Since this amounts to a major infringement of our rules, we are directing the BBC to broadcast a announcement of our determinations against it on BBC2 at 9pm, with a timing to be confirmed," the regulator stated.
'Risk to Erode Trust'
The authority's report declared: "Our probe concluded that the programme's lack of disclosure that the presenter's male guardian occupied a role in the Hamas-controlled administration was substantially inaccurate.
"It meant that the public did not have critical information which may have been highly relevant to their assessment of the presenter and the details he shared.
"Credibility is at the core of the connection between a television network and its public, notably for a public service broadcaster such as the BBC.
"This failing had the potential to erode the significantly high degrees of confidence that the public would have put in a factual film from the broadcaster about the Israel-Gaza war."
The programme was withdrawn from the BBC's streaming service in last February after the narrator's family links were revealed, and in the month of July an internal BBC review found it breached the broadcaster's editorial guidelines on truthfulness.
A representative for the broadcaster commented: "The Ofcom ruling is in accordance with the conclusions of Peter Johnston's review, that there was a serious error in the film in relation to the broadcaster's journalistic policies on accuracy, 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 follow the sanction as soon as the timing and wording are finalised."
