The BBC engaged in a "serious breach" of broadcasting rules by omitting to mention that the voice of a programme about the Gaza situation was the son of a Hamas official, according to British broadcasting authority Ofcom.
An probe by the media regulator into the documentary titled Gaza: How to Survive a Warzone has concluded that the programme was "substantially inaccurate".
The chief executive of the broadcaster had already issued an apology, saying there had been "a significant failing in relation to accuracy".
The regulator has directed the broadcaster to air a peak-time declaration about its conclusions.
"Since this amounts to a significant violation of our regulations, we are ordering the corporation to transmit a message of our findings against it on BBC Two at nine o'clock in the evening, with a date to be finalised," the regulator stated.
'Risk to Erode Trust'
The regulator's statement stated: "Our probe determined that the documentary's lack of disclosure that the narrator's male guardian held a position in the Hamas-administered administration was materially misleading.
"This implied that the viewers did not have vital facts which may have been highly relevant to their assessment of the presenter and the content he provided.
"Confidence is at the heart of the connection between a broadcaster and its public, especially for a public service broadcaster such as the BBC.
"This error had the possibility to erode the significantly high levels of trust that viewers would have invested in a documentary produced by the BBC about the Israel-Gaza war."
The programme was pulled from the BBC's streaming service in last February after the narrator's familial connections were revealed, and in this past July an internal BBC review found it infringed the corporation's journalistic standards on accuracy.
A corporation official commented: "The authority's determination is in accordance 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 corresponds to Rule 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we agree with the regulator's ruling in full. We will adhere to the penalty as soon as the timing and language are confirmed."
