The BBC committed a "major breach" of media regulations by omitting to mention that the voice of a film about the Gaza conflict was the son of a Hamas official, as determined by regulatory body Ofcom.
An investigation by the media regulator into the documentary titled Gaza: How to Survive a Warzone has found that the film was "substantially inaccurate".
The chief executive of the broadcaster had previously apologised, noting there had been "a significant failing in relation to accuracy".
The authority has ordered the BBC to broadcast a peak-time announcement about its findings.
"As this represents a serious breach of our regulations, we are instructing the broadcaster to air a announcement of our findings against it on the BBC's second channel at 21:00, with a schedule to be finalised," the regulator stated.
'Potential to Erode Trust'
The watchdog's report declared: "The inquiry we conducted concluded that the programme's failure to disclose that the narrator's father occupied a post in the Hamas-controlled administration was substantially inaccurate.
"Consequently that the viewers did not have essential details which may have been highly relevant to their evaluation of the presenter and the content he provided.
"Trust is at the heart of the connection between a television network and its public, notably for a state-funded media outlet such as the British Broadcasting Corporation.
"This failing had the possibility to damage the exceptionally strong levels of confidence that viewers would have placed in a factual film from the broadcaster about the conflict in Gaza."
The documentary was withdrawn from the online platform in February after the boy's familial connections emerged, and in this past July an broadcaster's internal assessment found it violated the corporation's journalistic standards on truthfulness.
A representative for the broadcaster said: "The Ofcom ruling is in accordance with the conclusions of the internal assessment, that there was a major oversight in the documentary in relation to the BBC's Editorial Guidelines on truthfulness, which aligns with regulation 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we accept Ofcom's decision in complete. We will follow the penalty as soon as the schedule and language are determined."
