The BBC engaged in a "significant breach" of broadcasting rules by failing to disclose that the voice of a programme about the Gaza situation was the child of a Hamas administrator, according to British broadcasting authority Ofcom.
An investigation by Ofcom into Gaza: How to Survive a Warzone has concluded that the film was "substantially inaccurate".
The head of the BBC had earlier expressed regret, noting there had been "a significant failing in relation to truthfulness".
The authority has instructed the BBC to transmit a evening announcement about its findings.
"As this represents a major infringement of our code, we are ordering the broadcaster to broadcast a statement of our findings against it on BBC2 at 9pm, with a date to be confirmed," it said.
'Possibility to Undermine Credibility'
The authority's statement declared: "Our probe determined that the documentary's failure to disclose that the narrator's parent occupied a role in the Hamas-run administration was significantly deceptive.
"It meant that the audience did not have essential details which may have been extremely pertinent to their assessment of the voice and the information he shared.
"Confidence is at the heart of the bond between a media organization and its public, particularly for a national broadcasting corporation such as the public broadcaster.
"This failing had the risk to undermine the very considerable levels of trust that the public would have invested in a factual film from the broadcaster about the Israel-Gaza war."
The programme was removed from the BBC's streaming service in February after the presenter's familial connections were revealed, and in the month of July an broadcaster's internal assessment found it violated the broadcaster's content policies on factual correctness.
A BBC spokesperson said: "The Ofcom ruling is in accordance with the results of Peter Johnston's review, that there was a serious error in the programme in relation to the BBC's Editorial Guidelines on accuracy, which aligns with regulation 2.2 of the regulator's media standards.
"We expressed regret for this and we agree with the authority's determination in complete. We will adhere to the directive as soon as the timing and wording are finalised."
