The British broadcaster was found to have committed a "significant breach" of industry standards by not revealing that the narrator of a film about Gaza was the offspring of a Hamas administrator, according to regulatory body Ofcom.
An investigation by the broadcasting watchdog into Gaza: How to Survive a Warzone has determined that the film was "materially misleading".
The BBC's director general had previously apologised, stating there had been "a significant failing in relation to factual correctness".
The regulator has instructed the corporation to air a peak-time statement about its conclusions.
"Given this constitutes a major infringement of our code, we are ordering the corporation to broadcast a message of our findings against it on BBC Two at 21:00, with a schedule to be finalised," the statement read.
'Possibility to Undermine Credibility'
The authority's report said: "Our investigation concluded that the documentary's lack of disclosure that the narrator's male guardian occupied a post in the Hamas-run government was significantly deceptive.
"It meant that the audience did not have vital facts which may have been extremely pertinent to their evaluation of the voice and the content he provided.
"Confidence is at the center of the connection between a media organization and its viewers, notably for a national broadcasting corporation such as the public broadcaster.
"This error had the risk to undermine the significantly high degrees of credibility that the public would have placed in a factual film from the broadcaster about the Israel-Gaza war."
The documentary was pulled from the BBC's streaming service in the month of February after the presenter's familial connections came to light, and in this past July an broadcaster's internal assessment found it violated the broadcaster's journalistic standards on accuracy.
A BBC spokesperson commented: "The authority's determination is in accordance with the results of Peter Johnston's review, that there was a significant failing in the documentary in relation to the corporation's content standards on truthfulness, which aligns with clause 2.2 of the regulator's media standards.
"We expressed regret for this and we comply with the regulator's ruling in its entirety. We will adhere to the directive as soon as the date and wording are finalised."
