The British broadcaster was found to have committed a "major breach" of industry standards by not revealing that the voice of a film about the Gaza conflict was the son of a Hamas official, as determined 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 significant failing in relation to accuracy".
The authority has instructed the broadcaster to broadcast a prime-time announcement about its conclusions.
"Given this constitutes a significant violation of our code, we are directing the BBC to broadcast a announcement of our findings against it on BBC2 at 21:00, with a timing to be confirmed," it said.
'Potential to Undermine Credibility'
The authority's report stated: "Our probe determined that the film's failure to disclose that the voice's father held a post in the Hamas-run administration was materially misleading.
"It meant that the audience did not have critical information which may have been very significant to their judgment of the narrator and the details he shared.
"Trust is at the center of the bond between a media organization and its public, particularly for a public service broadcaster such as the public broadcaster.
"This error had the risk to damage the exceptionally strong degrees of confidence that viewers would have placed in a documentary produced by the BBC about the Israel-Gaza war."
The documentary was removed from iPlayer in last February after the narrator's familial connections came to light, and in the month of July an broadcaster's internal assessment concluded it breached the organization's editorial guidelines on truthfulness.
A corporation official commented: "The regulator's decision is in line with the findings of the corporation's inquiry, that there was a serious error in the documentary in relation to the broadcaster's journalistic policies on factual correctness, which aligns with regulation 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we comply with the authority's determination in complete. We will comply with the directive as soon as the schedule and wording are confirmed."
