The British broadcaster was found to have committed a "significant breach" of industry standards by omitting to mention that the narrator of a programme about Gaza was the son of a Hamas official, as ruled by regulatory body Ofcom.
An probe by the media regulator into Gaza: How to Survive a Warzone has found that the documentary was "significantly deceptive".
The head of the BBC had already issued an apology, saying there had been "a significant failing in relation to factual correctness".
Ofcom has directed the broadcaster to broadcast a peak-time declaration about its decisions.
"As this represents a serious breach of our code, we are directing the BBC to broadcast a announcement of our findings against it on BBC2 at nine o'clock in the evening, with a timing to be finalised," the regulator stated.
'Possibility to Undermine Credibility'
The watchdog's report stated: "Our investigation found that the film's omission to reveal that the narrator's male guardian occupied a post in the Hamas-administered government was significantly deceptive.
"It meant that the public did not have vital facts which may have been highly relevant to their evaluation of the voice and the information he shared.
"Credibility is at the center of the relationship between a television network and its viewers, notably for a national broadcasting corporation such as the British Broadcasting Corporation.
"This error had the risk to damage the significantly high degrees of confidence that the public would have invested in a factual film from the broadcaster about the Israel-Gaza war."
The programme was withdrawn from the BBC's streaming service in the month of February after the presenter's personal associations came to light, and in the month of July an broadcaster's internal assessment found it breached the broadcaster's content policies on truthfulness.
A corporation official stated: "The Ofcom ruling is in accordance with the conclusions of Peter Johnston's review, that there was a serious error in the film in relation to the broadcaster's journalistic policies on truthfulness, which reflects clause 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we comply with Ofcom's decision in full. We will comply with the sanction as soon as the date and wording are determined."
