The BBC committed a "major breach" of broadcasting rules by not revealing that the presenter of a programme about Gaza was the child of a Hamas official, according to UK media regulator Ofcom.
An probe by the media regulator into the programme Gaza: How to Survive a Warzone has concluded that the documentary was "materially misleading".
The head of the BBC had already issued an apology, saying there had been "a significant failing in relation to accuracy".
The regulator has ordered the BBC to broadcast a peak-time declaration about its decisions.
"Given this constitutes a serious breach of our regulations, we are instructing the BBC to air a message of our findings against it on BBC2 at 9pm, with a date to be determined," the statement read.
'Possibility to Erode Trust'
The watchdog's statement stated: "Our probe concluded that the programme's failure to disclose that the presenter's father served in a position in the Hamas-run government was substantially inaccurate.
"Consequently that the audience did not have essential details which may have been very significant to their assessment of the voice and the content he shared.
"Confidence is at the center of the bond between a television network and its public, particularly for a public service broadcaster such as the BBC.
"This failing had the potential to undermine the exceptionally strong amounts of trust that the public would have placed in a factual film from the broadcaster about the Israel-Gaza war."
The film was withdrawn from the BBC's streaming service in the month of February after the narrator's personal associations were revealed, and in July an broadcaster's internal assessment determined it infringed the broadcaster's editorial guidelines on accuracy.
A BBC spokesperson said: "The Ofcom ruling is in line with the findings of the internal assessment, that there was a significant failing in the film in relation to the broadcaster's journalistic policies on truthfulness, which reflects Rule 2.2 of the regulator's media standards.
"We have apologised for this and we comply with the authority's determination in full. We will follow the directive as soon as the timing and wording are determined."
