The BBC committed a "major breach" of broadcasting rules by not revealing that the narrator of a programme about Gaza was the child of a Hamas official, according to UK media regulator Ofcom.
An investigation by the broadcasting watchdog into Gaza: How to Survive a Warzone has determined that the documentary was "significantly deceptive".
The head of the BBC had earlier expressed regret, stating there had been "a serious error in relation to factual correctness".
Ofcom has directed the broadcaster to broadcast a peak-time statement about its decisions.
"As this represents a significant violation of our rules, we are directing the BBC to air a announcement of our conclusions against it on BBC Two at 21:00, with a timing to be confirmed," it said.
'Possibility to Erode Trust'
The watchdog's statement said: "Our investigation found that the documentary's omission to reveal that the voice's male guardian occupied a position in the Hamas-administered administration was significantly deceptive.
"This implied that the public did not have critical information which may have been extremely pertinent to their judgment of the presenter and the information he presented.
"Credibility is at the heart of the connection between a media organization and its viewers, particularly for a public service broadcaster such as the British Broadcasting Corporation.
"This failing had the possibility to undermine the exceptionally strong amounts of confidence that audiences would have put in a factual film from the broadcaster about the Israel-Gaza war."
The film was pulled from the BBC's streaming service in February after the presenter's personal associations were revealed, and in July an broadcaster's internal assessment concluded it infringed the broadcaster's content policies on accuracy.
A BBC spokesperson commented: "The regulator's decision is in agreement with the findings of the internal assessment, that there was a serious error in the film in relation to the broadcaster's journalistic policies on factual correctness, which reflects clause 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we comply with Ofcom's decision in complete. We will adhere to the sanction as soon as the schedule and wording are determined."
