The British broadcaster engaged in a "significant breach" of broadcasting rules by failing to disclose that the narrator of a programme about the Gaza conflict was the son of a Hamas official, as determined by regulatory body Ofcom.
An inquiry by the broadcasting watchdog into the programme Gaza: How to Survive a Warzone has found that the programme was "materially misleading".
The head of the BBC had previously apologised, noting there had been "a serious error in relation to factual correctness".
The authority has directed the BBC to transmit a evening declaration about its findings.
"As this represents a significant violation of our rules, we are instructing the corporation to broadcast a message of our conclusions against it on the BBC's second channel at 21:00, with a schedule to be finalised," it said.
'Risk to Undermine Trust'
The regulator's statement declared: "Our investigation determined that the documentary's lack of disclosure that the voice's male guardian occupied a role in the Hamas-controlled government was substantially inaccurate.
"Consequently that the audience did not have critical information which may have been highly relevant to their evaluation of the presenter and the information he presented.
"Confidence is at the core of the relationship between a television network and its public, notably for a public service broadcaster such as the British Broadcasting Corporation.
"This oversight had the risk to erode the exceptionally strong degrees of trust that the public would have placed in a documentary produced by the BBC about the Gaza conflict."
The film was removed from the online platform in the month of February after the narrator's personal associations came to light, and in July an internal BBC review determined it violated the corporation's journalistic standards on factual correctness.
A BBC spokesperson said: "The authority's determination is in accordance with the conclusions of Peter Johnston's review, that there was a major oversight in the programme in relation to the corporation's content standards on accuracy, which aligns with Rule 2.2 of the regulator's media standards.
"We issued an apology for this and we agree with the regulator's ruling in full. We will comply with the penalty as soon as the date and wording are finalised."
