The public service broadcaster was found to have committed a "major breach" of media regulations by omitting to mention that the voice of a programme about the Gaza conflict was the offspring of a Hamas administrator, according to regulatory body Ofcom.
An investigation by the broadcasting watchdog into Gaza: How to Survive a Warzone has concluded that the programme was "substantially inaccurate".
The chief executive of the broadcaster had previously apologised, saying there had been "a significant failing in relation to factual correctness".
Ofcom has directed the corporation to broadcast a prime-time declaration about its conclusions.
"As this represents a serious breach of our regulations, we are instructing the corporation to transmit a announcement of our determinations against it on the BBC's second channel at nine o'clock in the evening, with a date to be confirmed," the statement read.
'Possibility to Undermine Confidence'
The regulator's announcement said: "Our probe concluded that the programme's lack of disclosure that the voice's parent held a position in the Hamas-run administration was materially misleading.
"This implied that the public did not have vital facts which may have been highly relevant to their judgment of the narrator and the content he provided.
"Confidence is at the heart of the relationship between a media organization and its audience, notably for a public service broadcaster such as the public broadcaster.
"This failing had the risk to undermine the significantly high degrees of confidence that the public would have invested in a factual film from the broadcaster about the conflict in Gaza."
The documentary was removed from iPlayer in February after the presenter's family links came to light, and in July an corporation's own inquiry found it infringed the corporation's journalistic standards on truthfulness.
A representative for the broadcaster said: "The authority's determination is in agreement with the findings of Peter Johnston's review, that there was a serious error in the documentary in relation to the broadcaster's journalistic policies on truthfulness, which aligns with clause 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we comply with the authority's determination in full. We will adhere to the directive as soon as the schedule and language are confirmed."
