The British broadcaster committed a "significant breach" of industry standards by failing to disclose that the voice of a film about the Gaza situation was the offspring of a Hamas administrator, as determined by regulatory body Ofcom.
An inquiry by the media regulator into the programme Gaza: How to Survive a Warzone has found that the film was "materially misleading".
The chief executive of the broadcaster had earlier expressed regret, saying there had been "a serious error in relation to accuracy".
The authority has instructed the BBC to transmit a evening declaration about its conclusions.
"As this represents a serious breach of our code, we are ordering the broadcaster to transmit a message of our determinations against it on BBC2 at 9pm, with a timing to be finalised," the statement read.
'Possibility to Damage Credibility'
The regulator's statement stated: "Our probe concluded that the programme's omission to reveal that the voice's parent served in a post in the Hamas-run administration was materially misleading.
"It meant that the viewers did not have essential details which may have been extremely pertinent to their evaluation of the presenter and the details he presented.
"Credibility is at the heart of the relationship between a broadcaster and its audience, notably for a national broadcasting corporation such as the BBC.
"This oversight had the possibility to damage the significantly high levels of credibility that audiences would have invested in a documentary produced by the BBC about the Israel-Gaza war."
The film was removed from the BBC's streaming service in the month of February after the presenter's personal associations were revealed, and in the month of July an corporation's own inquiry concluded it breached the broadcaster's content policies on accuracy.
A corporation official commented: "The Ofcom ruling is in agreement with the conclusions of Peter Johnston's review, that there was a serious error in the documentary in relation to the broadcaster's journalistic policies on truthfulness, which corresponds to Rule 2.2 of Ofcom's Broadcasting Code.
"We expressed regret for this and we accept the authority's determination in its entirety. We will adhere to the directive as soon as the schedule and wording are determined."
