The BBC committed a "serious breach" of media regulations by omitting to mention that the narrator of a programme about Gaza was the son of a Hamas administrator, as ruled by UK media regulator Ofcom.
An probe by the media regulator into Gaza: How to Survive a Warzone has concluded that the programme was "significantly deceptive".
The head of the BBC had earlier expressed regret, saying there had been "a significant failing in relation to accuracy".
The authority has directed the corporation to air a peak-time statement about its conclusions.
"Given this constitutes a serious breach of our regulations, we are directing the broadcaster to air a announcement of our conclusions against it on BBC Two at 9pm, with a schedule to be confirmed," the statement read.
'Risk to Undermine Trust'
The regulator's statement declared: "Our probe determined that the programme's lack of disclosure that the voice's father occupied a position in the Hamas-controlled government was materially misleading.
"Consequently that the public did not have critical information which may have been very significant to their judgment of the presenter and the information he presented.
"Trust is at the center of the bond between a media organization and its public, especially for a state-funded media outlet such as the British Broadcasting Corporation.
"This failing had the potential to damage the exceptionally strong levels of credibility that the public would have placed in a factual film from the broadcaster about the Gaza conflict."
The documentary was removed from iPlayer in February after the presenter's personal associations emerged, and in July an internal BBC review found it violated the broadcaster's journalistic standards on accuracy.
A representative for the broadcaster commented: "The regulator's decision is in agreement with the findings of the corporation's inquiry, that there was a serious error in the film in relation to the corporation's content standards on truthfulness, which reflects clause 2.2 of the regulator's media standards.
"We issued an apology for this and we comply with the authority's determination in its entirety. We will comply with the sanction as soon as the schedule and wording are confirmed."