The public service broadcaster committed a "major breach" of broadcasting rules by not revealing that the voice of a film about the Gaza conflict was the offspring of a Hamas official, according to regulatory body Ofcom.
An investigation by Ofcom into the programme Gaza: How to Survive a Warzone has concluded that the programme was "materially misleading".
The head of the BBC had earlier expressed regret, stating there had been "a significant failing in relation to truthfulness".
The authority has directed the BBC to air a prime-time announcement about its conclusions.
"Given this constitutes a major infringement of our rules, we are directing the broadcaster to broadcast a message of our findings against it on BBC2 at 9pm, with a date to be determined," it said.
'Possibility to Damage Trust'
The regulator's announcement said: "The inquiry we conducted determined that the programme's failure to disclose that the narrator's male guardian served in a post in the Hamas-administered government was materially misleading.
"It meant that the viewers did not have vital facts which may have been very significant to their evaluation of the presenter and the details he presented.
"Credibility is at the center of the relationship between a broadcaster and its public, especially for a state-funded media outlet such as the BBC.
"This oversight had the risk to damage the exceptionally strong amounts of credibility that audiences would have placed in a BBC factual programme about the Israel-Gaza war."
The documentary was pulled from the online platform in February after the presenter's personal associations emerged, and in the month of July an corporation's own inquiry found it violated the corporation's content policies on truthfulness.
A representative for the broadcaster commented: "The Ofcom ruling is in accordance with the conclusions of Peter Johnston's review, that there was a serious error in the programme in relation to the corporation's content standards on truthfulness, which reflects clause 2.2 of the regulator's media standards.
"We have apologised for this and we accept the authority's determination in its entirety. We will comply with the directive as soon as the schedule and language are determined."
