The public service broadcaster committed a "serious breach" of media regulations by not revealing that the narrator of a programme about the Gaza conflict was the child of a Hamas representative, according to British broadcasting authority Ofcom.
An inquiry by Ofcom into Gaza: How to Survive a Warzone has concluded that the film was "substantially inaccurate".
The BBC's director general had earlier expressed regret, saying there had been "a major oversight in relation to accuracy".
The regulator has instructed the broadcaster to broadcast a peak-time declaration about its findings.
"As this represents a major infringement of our rules, we are ordering the broadcaster to broadcast a message of our conclusions against it on BBC Two at nine o'clock in the evening, with a schedule to be determined," the statement read.
'Possibility to Undermine Confidence'
The watchdog's statement declared: "Our probe determined that the documentary's omission to reveal that the presenter's male guardian served in a position in the Hamas-run administration was significantly deceptive.
"Consequently that the public did not have essential details which may have been extremely pertinent to their evaluation of the voice and the information he presented.
"Confidence is at the heart of the connection between a television network and its viewers, especially for a public service broadcaster such as the public broadcaster.
"This error had the potential to undermine the exceptionally strong amounts of confidence that viewers would have placed in a factual film from the broadcaster about the conflict in Gaza."
The programme was pulled from the online platform in the month of February after the boy's personal associations emerged, and in this past July an broadcaster's internal assessment concluded it breached the broadcaster's editorial guidelines on accuracy.
A BBC spokesperson said: "The Ofcom ruling is in accordance with the results of the internal assessment, that there was a serious error in the programme in relation to the broadcaster's journalistic policies on factual correctness, 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 follow the sanction as soon as the date and wording are determined."
