The BBC engaged in a "major breach" of industry standards by omitting to mention that the voice of a film about the Gaza situation was the offspring of a Hamas representative, according to UK media regulator Ofcom.
An inquiry by Ofcom into the programme Gaza: How to Survive a Warzone has found that the film was "substantially inaccurate".
The head of the BBC had previously apologised, stating there had been "a major oversight in relation to truthfulness".
The regulator has directed the BBC to air a prime-time declaration about its decisions.
"Since this amounts to a serious breach of our regulations, we are directing the corporation to air a announcement of our determinations against it on the BBC's second channel at nine o'clock in the evening, with a timing to be determined," the statement read.
'Possibility to Erode Confidence'
The authority's statement said: "Our probe concluded that the film's lack of disclosure that the presenter's male guardian served in a position in the Hamas-administered government was significantly deceptive.
"This implied that the viewers did not have critical information which may have been highly relevant to their judgment of the narrator and the information he shared.
"Trust is at the core of the connection between a broadcaster and its viewers, especially for a public service broadcaster such as the BBC.
"This error had the possibility to erode the very considerable levels of trust that viewers would have invested in a documentary produced by the BBC about the conflict in Gaza."
The film was pulled from the BBC's streaming service in February after the presenter's personal associations emerged, and in the month of July an internal BBC review determined it breached the corporation's content policies on factual correctness.
A representative for the broadcaster said: "The regulator's decision is in agreement with the conclusions of the corporation's inquiry, that there was a serious error in the film in relation to the BBC's Editorial Guidelines on truthfulness, which corresponds to Rule 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we agree with Ofcom's decision in its entirety. We will adhere to the penalty as soon as the date and wording are confirmed."
