The public service broadcaster committed a "serious breach" of industry standards by omitting to mention that the narrator of a documentary about the Gaza conflict was the child of a Hamas representative, according to British broadcasting authority Ofcom.
An investigation by the broadcasting watchdog into Gaza: How to Survive a Warzone has determined that the documentary was "substantially inaccurate".
The BBC's director general had already issued an apology, noting there had been "a serious error in relation to factual correctness".
The regulator has ordered the BBC to transmit a peak-time announcement about its findings.
"Given this constitutes a significant violation of our regulations, we are directing the BBC to air a announcement of our determinations against it on BBC Two at nine o'clock in the evening, with a timing to be determined," the statement read.
'Potential to Damage Trust'
The watchdog's report stated: "The inquiry we conducted found that the programme's lack of disclosure that the voice's parent held a position in the Hamas-controlled authority was materially misleading.
"It meant that the audience did not have critical information which may have been very significant to their evaluation of the presenter and the information he presented.
"Confidence is at the heart of the relationship between a media organization and its audience, particularly for a national broadcasting corporation such as the BBC.
"This error had the possibility to undermine the exceptionally strong amounts of credibility that the public would have put in a factual film from the broadcaster about the Israel-Gaza war."
The programme was pulled from the online platform in February after the presenter's familial connections emerged, and in the month of July an internal BBC review found it breached the corporation's content policies on accuracy.
A BBC spokesperson stated: "The authority's determination is in line 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 truthfulness, which aligns with clause 2.2 of the regulator's media standards.
"We issued an apology for this and we comply with the authority's determination in its entirety. We will adhere to the sanction as soon as the timing and wording are determined."
