The BBC engaged in a "major breach" of broadcasting rules by not revealing that the narrator of a documentary about the Gaza situation was the child of a Hamas representative, as determined by British broadcasting authority Ofcom.
An investigation by Ofcom into Gaza: How to Survive a Warzone has determined that the film was "substantially inaccurate".
The chief executive of the broadcaster had already issued an apology, saying there had been "a serious error in relation to truthfulness".
Ofcom has directed the broadcaster to transmit a prime-time declaration about its conclusions.
"Given this constitutes a significant violation of our regulations, we are directing the BBC to transmit a statement of our determinations against it on the BBC's second channel at nine o'clock in the evening, with a timing to be confirmed," it said.
'Potential to Damage Confidence'
The authority's report said: "Our probe determined that the film's omission to reveal that the presenter's father held a post in the Hamas-run administration was substantially inaccurate.
"Consequently that the public did not have essential details which may have been highly relevant to their evaluation of the narrator and the content he provided.
"Credibility is at the core of the bond between a television network and its audience, especially for a public service broadcaster such as the public broadcaster.
"This error had the possibility to erode the very considerable levels of credibility that viewers would have invested in a factual film from the broadcaster about the Israel-Gaza war."
The programme was removed from the online platform in last February after the boy's familial connections were revealed, and in July an broadcaster's internal assessment determined it breached the organization's editorial guidelines on factual correctness.
A corporation official commented: "The regulator's decision is in agreement with the conclusions of Peter Johnston's review, that there was a significant failing in the documentary in relation to the BBC's Editorial Guidelines on accuracy, which reflects regulation 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we comply with the authority's determination in complete. We will follow the penalty as soon as the date and wording are confirmed."