The public service broadcaster committed a "major breach" of broadcasting rules by not revealing that the narrator of a programme about the Gaza situation was the son of a Hamas official, according to UK media regulator Ofcom.
An investigation by the media regulator into the programme Gaza: How to Survive a Warzone has concluded that the documentary was "significantly deceptive".
The BBC's director general had already issued an apology, saying there had been "a major oversight in relation to factual correctness".
Ofcom has directed the broadcaster to broadcast a peak-time statement about its conclusions.
"Since this amounts to a significant violation of our code, we are directing the corporation to air a message of our findings against it on BBC Two at 9pm, with a date to be finalised," the statement read.
'Risk to Damage Credibility'
The watchdog's statement stated: "The inquiry we conducted found that the programme's lack of disclosure that the presenter's father occupied a post in the Hamas-administered government was significantly deceptive.
"Consequently that the viewers did not have critical information which may have been extremely pertinent to their judgment of the narrator and the content he presented.
"Trust is at the core of the connection between a media organization and its public, particularly for a public service broadcaster such as the British Broadcasting Corporation.
"This failing had the potential to undermine the exceptionally strong degrees of trust that audiences would have placed in a factual film from the broadcaster about the Gaza conflict."
The film was withdrawn from iPlayer in February after the boy's familial connections emerged, and in July an broadcaster's internal assessment determined it infringed the organization's content policies on factual correctness.
A representative for the broadcaster stated: "The Ofcom ruling is in accordance with the findings of the corporation's inquiry, that there was a serious error in the film in relation to the BBC's Editorial Guidelines on accuracy, which reflects Rule 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we agree with Ofcom's decision in its entirety. We will adhere to the sanction as soon as the schedule and wording are determined."
