The public service broadcaster engaged in a "serious breach" of industry standards by failing to disclose that the narrator of a documentary about Gaza was the offspring of a Hamas administrator, as ruled by UK media regulator Ofcom.
An inquiry by Ofcom into Gaza: How to Survive a Warzone has found that the programme was "materially misleading".
The BBC's director general had already issued an apology, stating there had been "a major oversight in relation to truthfulness".
The regulator has directed the corporation to transmit a peak-time declaration about its conclusions.
"Given this constitutes a major infringement of our regulations, we are instructing the BBC to air a statement of our determinations against it on BBC Two at 21:00, with a schedule to be finalised," the statement read.
'Potential to Damage Trust'
The watchdog's announcement stated: "Our probe concluded that the film's lack of disclosure that the presenter's male guardian served in a role in the Hamas-run administration 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 shared.
"Trust is at the core of the relationship between a broadcaster and its public, especially for a national broadcasting corporation such as the public broadcaster.
"This failing had the risk to damage the very considerable levels of credibility that audiences would have placed in a BBC factual programme about the Israel-Gaza war."
The documentary was pulled from the BBC's streaming service in last February after the narrator's familial connections came to light, and in the month of July an broadcaster's internal assessment found it violated the corporation's content policies on accuracy.
A corporation official commented: "The authority's determination is in agreement with the findings of Peter Johnston's review, that there was a major oversight in the film in relation to the BBC's Editorial Guidelines on factual correctness, which reflects Rule 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we accept the regulator's ruling in its entirety. We will adhere to the penalty as soon as the date and wording are finalised."
