The British broadcaster engaged in a "major breach" of media regulations by not revealing that the voice of a programme about Gaza was the son of a Hamas official, as ruled by UK media regulator Ofcom.
An investigation by the broadcasting watchdog into the programme Gaza: How to Survive a Warzone has concluded that the programme was "significantly deceptive".
The chief executive of the broadcaster had earlier expressed regret, saying there had been "a serious error in relation to factual correctness".
The regulator has instructed the corporation to air a prime-time announcement about its findings.
"As this represents a major infringement of our regulations, we are instructing the corporation to air a statement of our determinations against it on the BBC's second channel at 9pm, with a timing to be confirmed," the statement read.
'Potential to Undermine Confidence'
The regulator's statement stated: "Our probe concluded that the documentary's lack of disclosure that the voice's parent held a post in the Hamas-controlled authority was materially misleading.
"This implied that the viewers did not have vital facts which may have been very significant to their evaluation of the presenter and the content he presented.
"Trust is at the center of the relationship between a media organization and its viewers, especially for a national broadcasting corporation such as the British Broadcasting Corporation.
"This oversight had the possibility to erode the significantly high levels of confidence that audiences would have invested in a BBC factual programme about the conflict in Gaza."
The film was pulled from iPlayer in February after the narrator's familial connections came to light, and in this past July an internal BBC review determined it breached the organization's editorial guidelines on truthfulness.
A representative for the broadcaster commented: "The Ofcom ruling is in agreement with the conclusions of Peter Johnston's review, that there was a serious error in the documentary in relation to the BBC's Editorial Guidelines on factual correctness, which aligns with clause 2.2 of the authority's broadcasting regulations.
"We have apologised for this and we agree with the regulator's ruling in complete. We will adhere to the penalty as soon as the date and language are confirmed."
