The British broadcaster engaged in a "serious breach" of broadcasting rules by failing to disclose that the narrator of a film about Gaza was the offspring of a Hamas official, according to UK media regulator Ofcom.
An inquiry by Ofcom into the programme Gaza: How to Survive a Warzone has found that the film was "substantially inaccurate".
The head of the BBC had earlier expressed regret, saying there had been "a serious error in relation to factual correctness".
The regulator has ordered the corporation to transmit a evening statement about its decisions.
"As this represents a significant violation of our code, we are ordering the corporation to broadcast a statement of our determinations against it on BBC Two at nine o'clock in the evening, with a schedule to be confirmed," it said.
'Potential to Erode Credibility'
The watchdog's announcement said: "The inquiry we conducted found that the documentary's lack of disclosure that the voice's male guardian occupied a role in the Hamas-controlled authority was substantially inaccurate.
"It meant that the viewers did not have critical information which may have been very significant to their judgment of the voice and the information he provided.
"Trust is at the core of the connection between a television network and its audience, particularly for a state-funded media outlet such as the BBC.
"This error had the possibility to erode the exceptionally strong amounts of credibility that the public would have placed in a BBC factual programme about the Gaza conflict."
The film 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 internal BBC review determined it breached the corporation's journalistic standards on truthfulness.
A representative for the broadcaster said: "The authority's determination is in agreement with the results of Peter Johnston's review, that there was a serious error in the documentary in relation to the BBC's Editorial Guidelines on accuracy, which corresponds to Rule 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we comply with Ofcom's decision in full. We will comply with the sanction as soon as the date and language are confirmed."
