The public service broadcaster engaged in a "major breach" of industry standards by failing to disclose that the narrator of a film about the Gaza conflict was the son of a Hamas representative, as determined by British broadcasting authority Ofcom.
An investigation by Ofcom into Gaza: How to Survive a Warzone has found that the programme was "significantly deceptive".
The chief executive of the broadcaster had previously apologised, noting there had been "a serious error in relation to truthfulness".
Ofcom has directed the broadcaster to broadcast a prime-time declaration about its conclusions.
"As this represents a major infringement of our regulations, we are directing the corporation to air a message of our findings against it on BBC Two at nine o'clock in the evening, with a timing to be confirmed," the regulator stated.
'Possibility to Undermine Trust'
The authority's statement said: "Our probe concluded that the film's failure to disclose that the presenter's father occupied a position in the Hamas-administered administration was significantly deceptive.
"It meant that the viewers did not have essential details which may have been very significant to their judgment of the narrator and the details he presented.
"Confidence is at the center of the connection between a broadcaster and its audience, particularly for a national broadcasting corporation such as the BBC.
"This error had the potential to undermine the exceptionally strong degrees of credibility that the public would have put in a BBC factual programme about the Gaza conflict."
The documentary was withdrawn from the online platform in last February after the presenter's family links emerged, and in this past July an corporation's own inquiry found it infringed the corporation's content policies on factual correctness.
A BBC spokesperson said: "The authority's determination is in accordance 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 truthfulness, which aligns with clause 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we accept the regulator's ruling in its entirety. We will follow the penalty as soon as the timing and language are confirmed."
