The British broadcaster was found to have committed a "significant breach" of industry standards by failing to disclose that the narrator of a film about the Gaza conflict was the child of a Hamas representative, as ruled by British broadcasting authority Ofcom.
An probe by the media regulator into Gaza: How to Survive a Warzone has found that the documentary was "substantially inaccurate".
The BBC's director general had previously apologised, saying there had been "a serious error in relation to factual correctness".
Ofcom has ordered the corporation to broadcast a evening announcement about its conclusions.
"Given this constitutes a serious breach of our code, we are directing the broadcaster to transmit a message of our determinations against it on BBC Two at 21:00, with a schedule to be confirmed," the regulator stated.
'Potential to Erode Credibility'
The regulator's statement stated: "Our investigation found that the programme's lack of disclosure that the voice's male guardian held a post in the Hamas-controlled authority was substantially inaccurate.
"It meant that the audience did not have vital facts which may have been very significant to their evaluation of the presenter and the content he presented.
"Trust is at the core of the relationship between a television network and its public, particularly for a national broadcasting corporation such as the BBC.
"This failing had the potential to undermine the very considerable amounts of credibility that viewers would have put in a documentary produced by the BBC about the Gaza conflict."
The documentary was pulled from iPlayer in last February after the narrator's familial connections came to light, and in July an internal BBC review concluded it breached the organization's content policies on accuracy.
A BBC spokesperson commented: "The Ofcom ruling is in agreement with the findings of the corporation's inquiry, that there was a major oversight in the documentary in relation to the BBC's Editorial Guidelines on factual correctness, which reflects Rule 2.2 of the authority's broadcasting regulations.
"We have apologised for this and we agree with the regulator's ruling in complete. We will adhere to the penalty as soon as the schedule and language are finalised."
