The public service broadcaster engaged in a "significant breach" of media regulations by failing to disclose that the voice of a film about the Gaza situation was the child of a Hamas administrator, according to regulatory body Ofcom.
An inquiry by Ofcom into Gaza: How to Survive a Warzone has found that the documentary was "substantially inaccurate".
The BBC's director general had previously apologised, noting there had been "a major oversight in relation to accuracy".
The regulator has directed the corporation to broadcast a prime-time statement about its decisions.
"As this represents a major infringement of our rules, we are directing the BBC to broadcast a message of our conclusions against it on BBC2 at nine o'clock in the evening, with a timing to be determined," the statement read.
'Potential to Undermine Trust'
The authority's announcement stated: "The inquiry we conducted determined that the documentary's omission to reveal that the narrator's male guardian served in a role in the Hamas-controlled government was substantially inaccurate.
"Consequently that the audience did not have critical information which may have been highly relevant to their assessment of the narrator and the information he provided.
"Credibility is at the center of the connection between a broadcaster and its audience, especially for a public service broadcaster such as the British Broadcasting Corporation.
"This error had the risk to undermine the significantly high levels of credibility that the public would have put in a BBC factual programme about the Israel-Gaza war."
The documentary was withdrawn from the online platform in the month of February after the narrator's personal associations were revealed, and in July an broadcaster's internal assessment concluded it violated the organization's editorial guidelines on factual correctness.
A representative for the broadcaster said: "The authority's determination is in agreement with the conclusions of the internal assessment, that there was a major oversight in the documentary in relation to the broadcaster's journalistic policies on factual correctness, which corresponds to Rule 2.2 of the regulator's media standards.
"We have apologised for this and we accept Ofcom's decision in its entirety. We will comply with the penalty as soon as the date and language are confirmed."
