The public service broadcaster engaged in a "major breach" of industry standards by omitting to mention that the presenter of a programme about Gaza was the offspring of a Hamas official, as determined by UK media regulator Ofcom.
An investigation by the media regulator into Gaza: How to Survive a Warzone has concluded that the programme was "substantially inaccurate".
The BBC's director general had previously apologised, saying there had been "a significant failing in relation to accuracy".
Ofcom has directed the BBC to broadcast a peak-time declaration about its decisions.
"Since this amounts to a major infringement of our code, we are ordering the corporation to transmit a announcement of our conclusions against it on BBC2 at nine o'clock in the evening, with a timing to be confirmed," the statement read.
'Risk to Undermine Trust'
The regulator's announcement declared: "Our probe concluded that the documentary's lack of disclosure that the narrator's parent served in a post in the Hamas-controlled government was materially misleading.
"Consequently that the public did not have vital facts which may have been very significant to their evaluation of the presenter and the content he presented.
"Confidence is at the center of the connection between a broadcaster and its viewers, notably for a public service broadcaster such as the public broadcaster.
"This failing had the possibility to erode the very considerable amounts of confidence that audiences would have invested in a documentary produced by the BBC about the Israel-Gaza war."
The documentary was withdrawn from iPlayer in last February after the presenter's family links were revealed, and in this past July an corporation's own inquiry concluded it breached the organization's journalistic standards on accuracy.
A representative for the broadcaster commented: "The authority's determination is in line with the results of the internal assessment, that there was a serious error in the documentary in relation to the corporation's content standards on accuracy, which reflects clause 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we comply with the authority's determination in its entirety. We will adhere to the sanction as soon as the schedule and language are determined."
