The BBC committed a "serious breach" of media regulations by omitting to mention that the voice of a documentary about the Gaza conflict was the offspring of a Hamas representative, as ruled by UK media regulator Ofcom.
An investigation by the broadcasting watchdog into the programme Gaza: How to Survive a Warzone has found that the documentary was "substantially inaccurate".
The chief executive of the broadcaster had earlier expressed regret, saying there had been "a major oversight in relation to accuracy".
The regulator has directed the corporation to broadcast a peak-time declaration about its conclusions.
"Given this constitutes a major infringement of our code, we are instructing the BBC to broadcast a announcement of our findings against it on BBC2 at 9pm, with a schedule to be determined," the statement read.
'Possibility to Erode Trust'
The regulator's announcement stated: "The inquiry we conducted concluded that the documentary's failure to disclose that the voice's male guardian held a post in the Hamas-controlled administration was materially misleading.
"This implied that the viewers did not have critical information which may have been highly relevant to their judgment of the voice and the content he presented.
"Credibility is at the center of the connection between a television network and its viewers, particularly for a state-funded media outlet such as the BBC.
"This failing had the possibility to damage the very considerable levels of confidence that viewers would have invested in a BBC factual programme about the conflict in Gaza."
The programme was removed from iPlayer in February after the boy's family links emerged, and in the month of July an internal BBC review found it infringed the corporation's content policies on truthfulness.
A representative for the broadcaster stated: "The Ofcom ruling is in agreement with the findings of the corporation's inquiry, that there was a major oversight in the documentary in relation to the broadcaster's journalistic policies on factual correctness, which reflects Rule 2.2 of Ofcom's Broadcasting Code.
"We expressed regret for this and we agree with the authority's determination in full. We will follow the penalty as soon as the date and wording are finalised."
