The British broadcaster committed a "serious breach" of industry standards by not revealing that the presenter of a film about the Gaza conflict was the child of a Hamas representative, as ruled by regulatory body Ofcom.
An probe by Ofcom into 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".
The authority has directed the BBC to broadcast a prime-time announcement about its findings.
"Since this amounts to a significant violation of our code, we are ordering the BBC to transmit a announcement of our findings against it on the BBC's second channel at 9pm, with a schedule to be finalised," the statement read.
'Risk to Erode Confidence'
The watchdog's announcement declared: "The inquiry we conducted concluded that the programme's lack of disclosure that the voice's male guardian occupied a role in the Hamas-controlled government was substantially inaccurate.
"It meant that the viewers did not have essential details which may have been highly relevant to their assessment of the voice and the details he provided.
"Trust is at the heart of the relationship between a television network and its viewers, especially for a national broadcasting corporation such as the BBC.
"This oversight had the possibility to erode the significantly high degrees of credibility that the public would have invested in a factual film from the broadcaster about the conflict in Gaza."
The documentary was removed from the online platform in the month of February after the narrator's familial connections emerged, and in this past July an internal BBC review concluded it breached the organization's content policies on truthfulness.
A BBC spokesperson said: "The regulator's decision is in agreement with the conclusions of the internal assessment, that there was a major oversight in the film in relation to the BBC's Editorial Guidelines on accuracy, which aligns with Rule 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we accept the authority's determination in its entirety. We will follow the penalty as soon as the date and wording are determined."
