The public service broadcaster committed a "significant breach" of industry standards by omitting to mention that the narrator of a programme about Gaza was the son of a Hamas administrator, according to UK media regulator Ofcom.
An probe by Ofcom into the programme Gaza: How to Survive a Warzone has determined that the programme was "substantially inaccurate".
The BBC's director general had previously apologised, stating there had been "a significant failing in relation to accuracy".
The regulator has ordered the broadcaster to transmit a prime-time declaration about its findings.
"As this represents a major infringement of our code, we are directing the corporation to broadcast a statement of our determinations against it on BBC Two at 21:00, with a schedule to be finalised," the regulator stated.
'Potential to Damage Credibility'
The regulator's statement declared: "The inquiry we conducted determined that the film's lack of disclosure that the presenter's parent held a role in the Hamas-run administration was significantly deceptive.
"It meant that the audience did not have vital facts which may have been very significant to their assessment of the voice and the details he provided.
"Credibility is at the center of the relationship between a television network and its viewers, notably for a state-funded media outlet such as the BBC.
"This error had the potential to undermine the significantly high amounts of trust that the public would have placed in a BBC factual programme about the Israel-Gaza war."
The documentary was withdrawn from the online platform in February after the narrator's familial connections were revealed, and in this past July an broadcaster's internal assessment found it violated the corporation's journalistic standards on truthfulness.
A representative for the broadcaster stated: "The authority's determination is in accordance with the findings of the internal assessment, that there was a major oversight 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 agree with the regulator's ruling in complete. We will adhere to the sanction as soon as the timing and wording are confirmed."
