The BBC engaged in a "serious breach" of broadcasting rules by omitting to mention that the presenter of a film about the Gaza situation was the son of a Hamas official, according to British broadcasting authority Ofcom.
An probe by Ofcom into Gaza: How to Survive a Warzone has concluded that the documentary was "substantially inaccurate".
The chief executive of the broadcaster had already issued an apology, saying there had been "a serious error in relation to accuracy".
The regulator has ordered the corporation to air a peak-time declaration about its decisions.
"As this represents a significant violation of our code, we are directing the corporation to broadcast a message of our determinations against it on BBC Two at nine o'clock in the evening, with a schedule to be determined," the regulator stated.
'Possibility to Damage Credibility'
The regulator's announcement stated: "Our probe determined that the film's omission to reveal that the voice's father held a post in the Hamas-controlled government was significantly deceptive.
"It meant that the audience did not have essential details which may have been highly relevant to their judgment of the voice and the information he provided.
"Confidence is at the center of the connection between a television network and its audience, especially for a state-funded media outlet such as the BBC.
"This error had the possibility to erode the exceptionally strong levels of credibility that the public would have put in a factual film from the broadcaster about the conflict in Gaza."
The film was pulled from the online platform in last February after the narrator's family links emerged, and in the month of July an internal BBC review determined it breached the corporation's journalistic standards on truthfulness.
A representative for the broadcaster stated: "The Ofcom ruling is in accordance with the conclusions of the internal assessment, that there was a significant failing in the film in relation to the BBC's Editorial Guidelines on accuracy, which reflects clause 2.2 of the regulator's media standards.
"We expressed regret for this and we agree with the regulator's ruling in its entirety. We will adhere to the penalty as soon as the timing and wording are finalised."
