The public service broadcaster was found to have committed a "significant breach" of industry standards by omitting to mention that the voice of a film about Gaza was the child of a Hamas representative, according to UK media regulator Ofcom.
An investigation by Ofcom into the programme Gaza: How to Survive a Warzone has concluded that the programme was "materially misleading".
The head of the BBC had earlier expressed regret, saying there had been "a serious error in relation to accuracy".
The authority has directed the corporation to transmit a prime-time announcement about its conclusions.
"As this represents a significant violation of our rules, we are ordering the broadcaster to air a announcement of our findings against it on BBC2 at 21:00, with a timing to be confirmed," it said.
'Risk to Undermine Confidence'
The watchdog's announcement declared: "The inquiry we conducted determined that the film's lack of disclosure that the narrator's male guardian held a post in the Hamas-run authority was substantially inaccurate.
"Consequently that the audience did not have critical information which may have been highly relevant to their evaluation of the narrator and the information he presented.
"Confidence is at the center of the relationship between a television network and its public, especially for a state-funded media outlet such as the BBC.
"This oversight had the possibility to undermine the exceptionally strong degrees of trust that audiences would have put in a BBC factual programme about the Gaza conflict."
The documentary was pulled from iPlayer in February after the presenter's family links were revealed, and in July an broadcaster's internal assessment concluded it violated the organization's journalistic standards on accuracy.
A BBC spokesperson commented: "The authority's determination is in agreement with the results of the internal assessment, that there was a major oversight in the film in relation to the broadcaster's journalistic policies on accuracy, which reflects Rule 2.2 of Ofcom's Broadcasting Code.
"We expressed regret for this and we comply with the regulator's ruling in full. We will follow the penalty as soon as the schedule and wording are finalised."
