The BBC committed a "significant breach" of media regulations by not revealing that the narrator of a film about Gaza was the child of a Hamas official, according to UK media regulator Ofcom.
An probe by the media regulator into Gaza: How to Survive a Warzone has concluded that the film was "substantially inaccurate".
The head of the BBC had already issued an apology, noting there had been "a major oversight in relation to truthfulness".
The regulator has ordered the broadcaster to broadcast a evening announcement about its findings.
"Since this amounts to a major infringement of our code, we are instructing the corporation to air a announcement of our findings against it on BBC2 at 9pm, with a timing to be finalised," it said.
'Possibility to Undermine Credibility'
The authority's statement stated: "The inquiry we conducted found that the film's lack of disclosure that the voice's parent served in a role in the Hamas-controlled administration was substantially inaccurate.
"Consequently that the viewers did not have essential details which may have been very significant to their judgment of the voice and the information he shared.
"Trust is at the heart of the bond between a broadcaster and its public, especially for a state-funded media outlet such as the British Broadcasting Corporation.
"This oversight had the potential to erode the very considerable degrees of credibility that the public would have placed in a BBC factual programme about the Israel-Gaza war."
The programme was pulled from the BBC's streaming service in last February after the narrator's familial connections emerged, and in this past July an broadcaster's internal assessment concluded it breached the organization's journalistic standards on truthfulness.
A BBC spokesperson said: "The Ofcom ruling is in accordance with the findings of the corporation's inquiry, that there was a significant failing in the programme in relation to the corporation's content standards on truthfulness, which corresponds to clause 2.2 of the regulator's media standards.
"We expressed regret for this and we comply with Ofcom's decision in full. We will follow the sanction as soon as the timing and wording are confirmed."
