The BBC was found to have committed a "serious breach" of media regulations by failing to disclose that the narrator of a programme about the Gaza conflict was the offspring of a Hamas representative, as ruled by British broadcasting authority Ofcom.
An probe by Ofcom into Gaza: How to Survive a Warzone has determined that the documentary was "significantly deceptive".
The BBC's director general had earlier expressed regret, saying there had been "a serious error in relation to accuracy".
The regulator has ordered the corporation to air a peak-time declaration about its conclusions.
"Since this amounts to a major infringement of our regulations, we are directing the BBC to broadcast a statement of our findings against it on the BBC's second channel at 21:00, with a date to be finalised," the statement read.
'Risk to Damage Trust'
The watchdog's announcement declared: "Our investigation concluded that the documentary's lack of disclosure that the voice's male guardian occupied a position in the Hamas-administered government was substantially inaccurate.
"Consequently that the audience did not have critical information which may have been very significant to their judgment of the narrator and the details he provided.
"Trust is at the core of the bond between a media organization and its public, notably for a public service broadcaster such as the BBC.
"This error had the possibility to undermine the exceptionally strong amounts of trust that viewers would have invested in a documentary produced by the BBC about the Israel-Gaza war."
The documentary was pulled from iPlayer in February after the presenter's familial connections emerged, and in July an broadcaster's internal assessment found it breached the organization's content policies on truthfulness.
A BBC spokesperson commented: "The authority's determination is in line with the results of the corporation's inquiry, that there was a major oversight in the film in relation to the corporation's content standards on truthfulness, which aligns with regulation 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we agree with Ofcom's decision in full. We will comply with the directive as soon as the date and wording are confirmed."
