The British broadcaster committed a "serious breach" of media regulations by omitting to mention that the voice of a documentary about Gaza was the offspring of a Hamas official, according to UK media regulator Ofcom.
An probe by the media regulator into Gaza: How to Survive a Warzone has concluded that the documentary was "significantly deceptive".
The BBC's director general had previously apologised, saying there had been "a major oversight in relation to truthfulness".
Ofcom has instructed the BBC to air a peak-time declaration about its conclusions.
"As this represents a serious breach of our regulations, we are ordering the corporation to air a announcement of our findings against it on BBC Two at 9pm, with a timing to be finalised," it said.
'Possibility to Undermine Confidence'
The regulator's statement declared: "Our probe found that the documentary's failure to disclose that the presenter's male guardian occupied a position in the Hamas-controlled administration was substantially inaccurate.
"It meant that the public did not have critical information which may have been very significant to their assessment of the narrator and the details he shared.
"Confidence is at the center of the relationship between a media organization and its public, especially for a national broadcasting corporation such as the public broadcaster.
"This oversight had the potential to damage the significantly high amounts of confidence that viewers would have invested in a documentary produced by the BBC about the Gaza conflict."
The documentary was pulled from the BBC's streaming service in February after the presenter's familial connections came to light, and in July an broadcaster's internal assessment found it violated the broadcaster's editorial guidelines on factual correctness.
A corporation official stated: "The authority's determination is in accordance with the findings of the corporation's inquiry, that there was a major oversight in the programme in relation to the corporation's content standards on truthfulness, which reflects clause 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we accept the regulator's ruling in full. We will follow the sanction as soon as the schedule and wording are determined."
