The BBC committed a "serious breach" of media regulations by omitting to mention that the voice of a programme about the Gaza situation was the son of a Hamas official, as determined by UK media regulator Ofcom.
An inquiry by Ofcom into the programme Gaza: How to Survive a Warzone has found that the film was "substantially inaccurate".
The head of the BBC had earlier expressed regret, stating there had been "a significant failing in relation to factual correctness".
Ofcom has instructed the corporation to air a prime-time statement about its findings.
"Since this amounts to a significant violation of our regulations, we are instructing the broadcaster to transmit a message of our findings against it on BBC2 at 21:00, with a timing to be determined," the regulator stated.
'Possibility to Undermine Confidence'
The watchdog's statement said: "Our probe concluded that the film's failure to disclose that the narrator's parent occupied a post in the Hamas-controlled government was materially misleading.
"Consequently that the public did not have critical information which may have been highly relevant to their evaluation of the presenter and the details he provided.
"Confidence is at the core of the relationship between a television network and its viewers, especially for a public service broadcaster such as the public broadcaster.
"This failing had the potential to damage the significantly high amounts of confidence that audiences would have placed in a factual film from the broadcaster about the conflict in Gaza."
The documentary was withdrawn from the online platform in the month of February after the boy's familial connections came to light, and in July an corporation's own inquiry concluded it breached the corporation's editorial guidelines on accuracy.
A corporation official said: "The Ofcom ruling is in line with the findings of the corporation's inquiry, that there was a significant failing in the documentary in relation to the broadcaster's journalistic policies on accuracy, which aligns with regulation 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we agree with the regulator's ruling in its entirety. We will comply with the sanction as soon as the timing and wording are finalised."
