The public service broadcaster engaged in a "major breach" of broadcasting rules by not revealing that the narrator of a documentary about Gaza was the child of a Hamas representative, according to British broadcasting authority Ofcom.
An inquiry by Ofcom into Gaza: How to Survive a Warzone has concluded that the programme was "substantially inaccurate".
The head of the BBC had previously apologised, saying there had been "a serious error in relation to factual correctness".
The authority has directed the corporation to broadcast a peak-time declaration about its decisions.
"Since this amounts to a major infringement of our regulations, we are directing the BBC to air a message of our findings against it on BBC Two at 21:00, with a date to be determined," it said.
'Potential to Erode Trust'
The regulator's statement said: "Our investigation concluded that the programme's lack of disclosure that the narrator's male guardian occupied a post in the Hamas-controlled government was significantly deceptive.
"Consequently that the audience did not have critical information which may have been highly relevant to their judgment of the presenter and the content he provided.
"Trust is at the center of the connection between a broadcaster and its audience, particularly for a state-funded media outlet such as the British Broadcasting Corporation.
"This error had the possibility to undermine the significantly high levels of trust that viewers would have placed in a factual film from the broadcaster about the Gaza conflict."
The programme was pulled from the online platform in February after the presenter's personal associations emerged, and in this past July an internal BBC review found it violated the organization's editorial guidelines on factual correctness.
A corporation official commented: "The Ofcom ruling is in line with the findings of the corporation's inquiry, that there was a serious error in the documentary in relation to the broadcaster's journalistic policies on truthfulness, which aligns with regulation 2.2 of Ofcom's Broadcasting Code.
"We expressed regret for this and we accept the regulator's ruling in full. We will follow the sanction as soon as the schedule and wording are determined."
