The BBC engaged in a "significant breach" of broadcasting rules by omitting to mention that the narrator of a programme about the Gaza situation was the son of a Hamas official, as ruled by regulatory body Ofcom.
An investigation by Ofcom into Gaza: How to Survive a Warzone has found that the documentary was "significantly deceptive".
The head of the BBC had already issued an apology, noting there had been "a serious error in relation to accuracy".
Ofcom has ordered the corporation to transmit a peak-time announcement about its findings.
"As this represents a serious breach of our rules, we are directing the BBC to broadcast a statement of our conclusions against it on the BBC's second channel at nine o'clock in the evening, with a date to be determined," the regulator stated.
'Risk to Undermine Credibility'
The authority's report said: "The inquiry we conducted found that the programme's omission to reveal that the voice's male guardian occupied a post in the Hamas-controlled government was materially misleading.
"It meant that the viewers did not have critical information which may have been very significant to their judgment of the voice and the content he shared.
"Credibility is at the center of the relationship between a media organization and its public, particularly for a public service broadcaster such as the British Broadcasting Corporation.
"This error had the potential to undermine the significantly high levels of trust that audiences would have invested in a factual film from the broadcaster about the Gaza conflict."
The programme was pulled from the online platform in the month of February after the presenter's family links emerged, and in July an internal BBC review found it violated the corporation's content policies on factual correctness.
A representative for the broadcaster commented: "The Ofcom ruling is in accordance with the findings of the corporation's inquiry, that there was a major oversight in the documentary in relation to the broadcaster's journalistic policies on accuracy, which reflects clause 2.2 of the regulator's media standards.
"We have apologised for this and we accept Ofcom's decision in complete. We will follow the penalty as soon as the date and wording are finalised."
