The public service broadcaster committed a "serious breach" of broadcasting rules by not revealing that the narrator of a documentary about Gaza was the child of a Hamas official, as ruled by UK media regulator Ofcom.
An probe by Ofcom into the programme Gaza: How to Survive a Warzone has found that the programme was "substantially inaccurate".
The BBC's director general had previously apologised, saying there had been "a major oversight in relation to truthfulness".
The regulator has instructed the corporation to transmit a evening declaration about its conclusions.
"As this represents a serious breach of our code, we are instructing the BBC to transmit a announcement of our findings against it on the BBC's second channel at nine o'clock in the evening, with a schedule to be determined," the statement read.
'Possibility to Erode Credibility'
The watchdog's statement stated: "Our probe determined that the documentary's omission to reveal that the presenter's parent served in a post in the Hamas-controlled administration was substantially inaccurate.
"This implied that the audience did not have vital facts which may have been highly relevant to their judgment of the presenter and the content he presented.
"Credibility is at the center of the relationship between a media organization and its audience, especially for a state-funded media outlet such as the BBC.
"This oversight had the potential to erode the exceptionally strong amounts of trust that audiences would have put 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 familial connections came to light, and in this past July an internal BBC review concluded it infringed the broadcaster's journalistic standards on factual correctness.
A corporation official commented: "The Ofcom ruling is in agreement with the conclusions of Peter Johnston's review, that there was a major oversight in the documentary in relation to the BBC's Editorial Guidelines on truthfulness, which reflects Rule 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we comply with Ofcom's decision in its entirety. We will comply with the sanction as soon as the timing and wording are finalised."
