The British broadcaster engaged in a "major breach" of broadcasting rules by omitting to mention that the narrator of a programme about the Gaza situation was the offspring of a Hamas administrator, as determined by British broadcasting authority Ofcom.
An inquiry by the broadcasting watchdog into the programme Gaza: How to Survive a Warzone has concluded that the documentary was "materially misleading".
The BBC's director general had earlier expressed regret, noting there had been "a serious error in relation to accuracy".
Ofcom has ordered the BBC to broadcast a prime-time announcement about its findings.
"Given this constitutes a major infringement of our code, we are ordering the corporation to transmit a announcement of our conclusions against it on the BBC's second channel at 21:00, with a schedule to be determined," the regulator stated.
'Possibility to Damage Credibility'
The authority's statement declared: "Our investigation found that the documentary's omission to reveal that the narrator's male guardian held a role in the Hamas-administered administration was materially misleading.
"Consequently that the public did not have essential details which may have been extremely pertinent to their assessment of the presenter and the content he provided.
"Credibility is at the heart of the relationship between a broadcaster and its audience, especially for a public service broadcaster such as the British Broadcasting Corporation.
"This oversight had the potential to erode the exceptionally strong degrees of confidence that audiences would have invested in a factual film from the broadcaster about the conflict in Gaza."
The documentary was removed from iPlayer in last February after the narrator's family links were revealed, and in the month of July an corporation's own inquiry determined it breached the corporation's journalistic standards on accuracy.
A BBC spokesperson said: "The regulator's decision is in accordance with the conclusions of the internal assessment, that there was a major oversight in the programme in relation to the BBC's Editorial Guidelines on accuracy, which reflects regulation 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we agree with the regulator's ruling in full. We will adhere to the penalty as soon as the date and language are determined."
