The British broadcaster was found to have committed a "serious breach" of industry standards by failing to disclose that the narrator of a programme about the Gaza situation was the son of a Hamas representative, according to regulatory body Ofcom.
An inquiry by the broadcasting watchdog into Gaza: How to Survive a Warzone has concluded that the film was "significantly deceptive".
The BBC's director general had already issued an apology, noting there had been "a serious error in relation to truthfulness".
The regulator has directed the corporation to air a peak-time announcement about its findings.
"Since this amounts to a significant violation of our rules, we are directing the corporation to air a message of our determinations against it on BBC2 at nine o'clock in the evening, with a timing to be determined," it said.
'Possibility to Undermine Credibility'
The authority's report stated: "Our probe determined that the film's omission to reveal that the presenter's parent occupied a role in the Hamas-run government was substantially inaccurate.
"This implied that the viewers did not have critical information which may have been very significant to their judgment of the narrator and the details he shared.
"Credibility is at the center of the relationship between a media organization and its public, especially for a state-funded media outlet such as the British Broadcasting Corporation.
"This error had the possibility to erode the exceptionally strong amounts of confidence that audiences would have put in a documentary produced by the BBC about the Gaza conflict."
The programme was pulled from iPlayer in February after the presenter's family links emerged, and in this past July an corporation's own inquiry determined it infringed the organization's editorial guidelines on accuracy.
A BBC spokesperson commented: "The regulator's decision is in agreement with the results of Peter Johnston's review, that there was a serious error in the film in relation to the corporation's content standards on accuracy, which reflects regulation 2.2 of Ofcom's Broadcasting Code.
"We expressed regret for this and we accept the regulator's ruling in its entirety. We will comply with the penalty as soon as the date and language are determined."
