The British broadcaster was found to have committed a "significant breach" of broadcasting rules by not revealing that the narrator of a film about the Gaza conflict was the offspring of a Hamas representative, according to British broadcasting authority Ofcom.
An probe by the broadcasting watchdog into Gaza: How to Survive a Warzone has found that the film was "significantly deceptive".
The BBC's director general had already issued an apology, stating there had been "a major oversight in relation to truthfulness".
The regulator has directed the BBC to broadcast a peak-time declaration about its findings.
"Given this constitutes a significant violation of our rules, we are instructing the broadcaster to broadcast a message of our determinations against it on the BBC's second channel at 21:00, with a timing to be confirmed," the regulator stated.
'Potential to Erode Credibility'
The authority's statement stated: "The inquiry we conducted determined that the documentary's omission to reveal that the narrator's male guardian held a role in the Hamas-controlled authority was substantially inaccurate.
"Consequently that the public did not have critical information which may have been very significant to their judgment of the narrator and the content he shared.
"Credibility is at the center of the bond between a broadcaster and its viewers, especially for a state-funded media outlet such as the British Broadcasting Corporation.
"This failing had the risk to undermine the significantly high levels of confidence that the public would have put in a factual film from the broadcaster about the Israel-Gaza war."
The programme was pulled from the online platform in last February after the presenter's familial connections emerged, and in this past July an corporation's own inquiry determined it violated the broadcaster's content policies on factual correctness.
A representative for the broadcaster said: "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 accuracy, which aligns with clause 2.2 of the authority's broadcasting regulations.
"We have apologised for this and we comply with the authority's determination in complete. We will follow the penalty as soon as the schedule and wording are determined."
