The public service broadcaster committed a "significant breach" of industry standards by not revealing that the voice of a documentary about the Gaza situation was the offspring of a Hamas official, according to British broadcasting authority Ofcom.
An investigation by Ofcom into Gaza: How to Survive a Warzone has concluded that the film was "significantly deceptive".
The chief executive of the broadcaster had already issued an apology, saying there had been "a significant failing in relation to accuracy".
The regulator has instructed the BBC to broadcast a prime-time statement about its decisions.
"As this represents a major infringement of our regulations, we are directing the broadcaster to air a announcement 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 Erode Credibility'
The regulator's announcement stated: "The inquiry we conducted concluded that the documentary's omission to reveal that the voice's male guardian held a post in the Hamas-administered government was substantially inaccurate.
"It meant that the viewers did not have essential details which may have been highly relevant to their assessment of the narrator and the content he provided.
"Confidence is at the heart of the bond between a television network and its viewers, particularly for a public service broadcaster such as the public broadcaster.
"This failing had the potential to damage the very considerable levels of credibility that audiences would have invested in a documentary produced by the BBC about the Israel-Gaza war."
The documentary was pulled from the online platform in last February after the boy's personal associations were revealed, and in July an corporation's own inquiry determined it violated the organization's editorial guidelines on accuracy.
A BBC spokesperson commented: "The authority's determination is in line with the conclusions of the internal assessment, that there was a significant failing in the documentary in relation to the broadcaster's journalistic policies on factual correctness, which corresponds to clause 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we accept the authority's determination in complete. We will comply with the penalty as soon as the schedule and wording are finalised."
