The British broadcaster engaged in a "serious breach" of media regulations by not revealing that the voice of a documentary about the Gaza situation was the son of a Hamas representative, as ruled by regulatory body Ofcom.
An inquiry by the media regulator into the programme Gaza: How to Survive a Warzone has determined that the programme was "significantly deceptive".
The BBC's director general had previously apologised, stating there had been "a major oversight in relation to accuracy".
Ofcom has instructed the BBC to air a evening declaration about its conclusions.
"Since this amounts to a major infringement of our rules, we are instructing the broadcaster to broadcast a statement of our conclusions against it on BBC Two at nine o'clock in the evening, with a timing to be finalised," the statement read.
'Potential to Undermine Trust'
The regulator's report stated: "The inquiry we conducted determined that the programme's omission to reveal that the voice's father held a post in the Hamas-administered government was significantly deceptive.
"Consequently that the public did not have critical information which may have been highly relevant to their assessment of the narrator and the information he shared.
"Trust is at the core of the bond between a television network and its audience, particularly for a state-funded media outlet such as the public broadcaster.
"This oversight had the potential to erode the exceptionally strong degrees of confidence that the public would have placed in a factual film from the broadcaster about the Gaza conflict."
The programme was pulled from the BBC's streaming service in February after the presenter's family links were revealed, and in July an corporation's own inquiry determined it breached the corporation's content policies on accuracy.
A corporation official stated: "The authority's determination is in agreement with the findings of the corporation's inquiry, that there was a major oversight in the film in relation to the broadcaster's journalistic policies on accuracy, which reflects regulation 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we accept the authority's determination in complete. We will comply with the penalty as soon as the date and wording are confirmed."
