The British broadcaster was found to have committed a "major breach" of media regulations by not revealing that the narrator of a film about the Gaza situation was the offspring of a Hamas representative, as determined by regulatory body Ofcom.
An investigation by Ofcom into Gaza: How to Survive a Warzone has concluded that the programme was "substantially inaccurate".
The head of the BBC had previously apologised, noting there had been "a serious error in relation to factual correctness".
Ofcom has ordered the BBC to air a prime-time declaration about its findings.
"Given this constitutes a serious breach of our rules, we are instructing the BBC to air a statement of our findings against it on BBC Two at nine o'clock in the evening, with a schedule to be determined," it said.
'Risk to Damage Trust'
The watchdog's statement declared: "The inquiry we conducted concluded that the documentary's failure to disclose that the narrator's male guardian occupied a role in the Hamas-run authority was significantly deceptive.
"This implied that the public did not have vital facts which may have been highly relevant to their judgment of the narrator and the information he presented.
"Credibility is at the core of the relationship between a television network and its public, particularly for a national broadcasting corporation such as the British Broadcasting Corporation.
"This error had the potential to erode the very considerable levels of trust that viewers would have invested in a BBC factual programme about the Gaza conflict."
The film was removed from iPlayer in the month of February after the narrator's familial connections came to light, and in July an broadcaster's internal assessment concluded it infringed the corporation's editorial guidelines on truthfulness.
A corporation official commented: "The regulator's decision is in agreement with the conclusions of the internal assessment, that there was a significant failing in the film in relation to the BBC's Editorial Guidelines on truthfulness, which reflects Rule 2.2 of the regulator's media standards.
"We expressed regret for this and we accept Ofcom's decision in complete. We will follow the penalty as soon as the date and wording are confirmed."
