The British broadcaster engaged in a "significant breach" of broadcasting rules by failing to disclose that the voice of a film about Gaza was the offspring of a Hamas official, as determined by British broadcasting authority Ofcom.
An probe by the broadcasting watchdog into Gaza: How to Survive a Warzone has determined that the documentary was "materially misleading".
The BBC's director general had previously apologised, saying there had been "a significant failing in relation to accuracy".
Ofcom has directed the broadcaster to broadcast a prime-time announcement about its conclusions.
"As this represents a serious breach of our rules, we are ordering the BBC to broadcast a announcement of our determinations against it on the BBC's second channel at nine o'clock in the evening, with a timing to be confirmed," it said.
'Possibility to Damage Credibility'
The authority's statement stated: "Our investigation concluded that the film's failure to disclose that the narrator's male guardian held a position in the Hamas-administered administration was significantly deceptive.
"Consequently that the audience did not have essential details which may have been highly relevant to their evaluation of the presenter and the details he presented.
"Confidence is at the heart of the relationship between a media organization and its public, notably for a state-funded media outlet such as the BBC.
"This oversight had the possibility to undermine the significantly high degrees of credibility that the public would have placed in a documentary produced by the BBC about the conflict in Gaza."
The documentary was pulled 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 determined it infringed the organization's journalistic standards on truthfulness.
A BBC spokesperson stated: "The Ofcom ruling is in agreement with the results of Peter Johnston's review, that there was a serious error in the documentary in relation to the corporation's content standards on accuracy, which corresponds to clause 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we accept the regulator's ruling in full. We will comply with the directive as soon as the timing and language are determined."
