The public service broadcaster engaged in a "significant breach" of media regulations by not revealing that the narrator of a programme about Gaza was the son of a Hamas representative, as ruled by British broadcasting authority Ofcom.
An inquiry by the media regulator into the documentary titled Gaza: How to Survive a Warzone has concluded that the film was "materially misleading".
The BBC's director general had previously apologised, saying there had been "a serious error in relation to accuracy".
The regulator has ordered the corporation to transmit a peak-time announcement about its conclusions.
"As this represents a serious breach of our code, we are directing the corporation to transmit a message of our findings against it on BBC2 at 21:00, with a timing to be determined," it said.
'Possibility to Damage Credibility'
The regulator's report declared: "The inquiry we conducted found that the film's omission to reveal that the presenter's male guardian held a position in the Hamas-administered administration was materially misleading.
"It meant that the public did not have essential details which may have been very significant to their judgment of the narrator and the information he presented.
"Confidence is at the core of the connection between a media organization and its public, notably for a national broadcasting corporation such as the public broadcaster.
"This failing had the potential to erode the significantly high amounts of credibility that viewers would have put in a factual film from the broadcaster about the Gaza conflict."
The programme was removed from the BBC's streaming service in last February after the narrator's personal associations emerged, and in this past July an corporation's own inquiry concluded it violated the organization's editorial guidelines on truthfulness.
A representative for the broadcaster commented: "The Ofcom ruling is in line with the results of Peter Johnston's review, that there was a major oversight in the documentary in relation to the BBC's Editorial Guidelines on accuracy, which reflects Rule 2.2 of the regulator's media standards.
"We have apologised for this and we accept Ofcom's decision in complete. We will adhere to the penalty as soon as the schedule and wording are confirmed."
