The BBC committed a "serious breach" of industry standards by not revealing that the voice of a documentary about the Gaza conflict was the son of a Hamas official, as ruled by British broadcasting authority Ofcom.
An investigation by the media regulator into Gaza: How to Survive a Warzone has determined that the documentary was "substantially inaccurate".
The chief executive of the broadcaster had earlier expressed regret, noting there had been "a significant failing in relation to accuracy".
The authority has directed the broadcaster to air a evening statement about its decisions.
"As this represents a serious breach of our code, we are instructing the corporation to transmit a announcement of our conclusions against it on BBC Two at 21:00, with a timing to be finalised," the statement read.
'Potential to Erode Credibility'
The regulator's statement declared: "The inquiry we conducted determined that the film's lack of disclosure that the presenter's father served in a post in the Hamas-run government was substantially inaccurate.
"It meant that the viewers did not have critical information which may have been highly relevant to their judgment of the narrator and the details he presented.
"Trust is at the heart of the relationship between a television network and its audience, notably for a public service broadcaster such as the BBC.
"This failing had the potential to erode the very considerable levels of trust that audiences would have put in a documentary produced by the BBC about the conflict in Gaza."
The documentary was removed from the BBC's streaming service in the month of February after the boy's family links emerged, and in the month of July an broadcaster's internal assessment found it breached the corporation's journalistic standards on truthfulness.
A representative for the broadcaster commented: "The Ofcom ruling is in line with the findings of Peter Johnston's review, that there was a significant failing in the film in relation to the corporation's content standards on accuracy, which aligns with Rule 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we accept Ofcom's decision in full. We will comply with the penalty as soon as the schedule and language are finalised."
