The public service broadcaster committed a "significant breach" of broadcasting rules by failing to disclose that the narrator of a documentary about Gaza was the child of a Hamas representative, as determined by UK media regulator Ofcom.
An inquiry by the broadcasting watchdog into the documentary titled Gaza: How to Survive a Warzone has concluded that the film was "materially misleading".
The head of the BBC had earlier expressed regret, noting there had been "a serious error in relation to truthfulness".
The regulator has instructed the broadcaster to transmit a peak-time declaration about its decisions.
"Since this amounts to a major infringement of our regulations, we are instructing the broadcaster to broadcast a statement of our conclusions against it on the BBC's second channel at 9pm, with a timing to be finalised," the statement read.
'Risk to Damage Credibility'
The regulator's statement stated: "Our investigation found that the programme's omission to reveal that the narrator's male guardian held a post in the Hamas-run government was significantly deceptive.
"It meant that the audience did not have vital facts which may have been highly relevant to their assessment of the voice and the details he shared.
"Confidence is at the center of the relationship between a broadcaster and its public, particularly for a national broadcasting corporation such as the British Broadcasting Corporation.
"This oversight had the possibility to erode the significantly high amounts of credibility that viewers would have put in a BBC factual programme about the conflict in Gaza."
The film was removed from iPlayer in February after the presenter's familial connections came to light, and in the month of July an corporation's own inquiry concluded it breached the broadcaster's editorial guidelines on accuracy.
A BBC spokesperson commented: "The regulator's decision is in accordance with the results of Peter Johnston's review, that there was a major oversight in the film in relation to the broadcaster's journalistic policies on truthfulness, which aligns with Rule 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we accept Ofcom's decision in complete. We will follow the penalty as soon as the schedule and language are determined."
