The British broadcaster was found to have committed a "serious breach" of media regulations by omitting to mention that the narrator of a programme about Gaza was the son of a Hamas representative, as determined by regulatory body Ofcom.
An inquiry by the media regulator into the programme Gaza: How to Survive a Warzone has concluded that the programme was "substantially inaccurate".
The head of the BBC had already issued an apology, stating there had been "a significant failing in relation to accuracy".
The authority has ordered the BBC to broadcast a peak-time announcement about its decisions.
"As this represents a major infringement of our code, we are instructing the BBC to transmit a announcement of our conclusions against it on the BBC's second channel at 9pm, with a schedule to be finalised," it said.
'Risk to Undermine Confidence'
The authority's report said: "The inquiry we conducted determined that the documentary's lack of disclosure that the narrator's male guardian served in a position in the Hamas-administered administration was materially misleading.
"It meant that the public did not have vital facts which may have been extremely pertinent to their evaluation of the voice and the information he provided.
"Confidence is at the heart of the connection between a media organization and its audience, especially for a state-funded media outlet such as the British Broadcasting Corporation.
"This error had the possibility to undermine the exceptionally strong levels of trust that viewers would have invested in a factual film from the broadcaster about the conflict in Gaza."
The documentary was withdrawn from the online platform in February after the narrator's familial connections came to light, and in July an internal BBC review concluded it breached the broadcaster's journalistic standards on accuracy.
A BBC spokesperson commented: "The Ofcom ruling is in line with the conclusions of the internal assessment, that there was a serious error in the programme in relation to the corporation's content standards on accuracy, which reflects regulation 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we agree with Ofcom's decision in its entirety. We will follow the sanction as soon as the schedule and language are determined."
