The British broadcaster committed a "serious breach" of media regulations by omitting to mention that the voice of a documentary about the Gaza situation was the child of a Hamas representative, as determined by regulatory body Ofcom.
An inquiry by Ofcom into the documentary titled Gaza: How to Survive a Warzone has determined that the documentary was "significantly deceptive".
The BBC's director general had earlier expressed regret, saying there had been "a major oversight in relation to accuracy".
The authority has directed the broadcaster to air a prime-time announcement about its conclusions.
"As this represents a serious breach of our rules, we are instructing the corporation to transmit a announcement of our findings against it on the BBC's second channel at 9pm, with a timing to be finalised," it said.
'Possibility to Erode Confidence'
The watchdog's statement declared: "Our probe determined that the film's lack of disclosure that the presenter's parent served in a post in the Hamas-run government was significantly deceptive.
"Consequently that the audience did not have vital facts which may have been highly relevant to their judgment of the narrator and the content he presented.
"Trust is at the core of the bond between a media organization and its audience, especially for a public service broadcaster such as the BBC.
"This oversight had the potential to erode the exceptionally strong degrees of trust that the public would have put in a BBC factual programme about the Israel-Gaza war."
The documentary was pulled from the online platform in last February after the narrator's familial connections came to light, and in July an internal BBC review found it violated the corporation's editorial guidelines on truthfulness.
A BBC spokesperson said: "The Ofcom ruling is in accordance with the results of the internal assessment, that there was a significant failing in the film in relation to the corporation's content standards on factual correctness, which reflects clause 2.2 of the regulator's media standards.
"We expressed regret for this and we accept the regulator's ruling in its entirety. We will follow the penalty as soon as the date and wording are confirmed."
