The BBC was found to have committed a "significant breach" of broadcasting rules by failing to disclose that the narrator of a programme about Gaza was the offspring of a Hamas representative, as determined by regulatory body Ofcom.
An probe by the media regulator into the programme Gaza: How to Survive a Warzone has concluded that the film was "significantly deceptive".
The BBC's director general had earlier expressed regret, noting there had been "a significant failing in relation to accuracy".
Ofcom has directed the corporation to broadcast a evening declaration about its findings.
"As this represents a major infringement of our code, we are directing the corporation to broadcast a message of our determinations against it on BBC Two at 21:00, with a timing to be confirmed," it said.
'Risk to Erode Trust'
The watchdog's statement said: "The inquiry we conducted found that the film's failure to disclose that the voice's male guardian served in a post in the Hamas-controlled government was materially misleading.
"It meant that the public did not have vital facts which may have been very significant to their assessment of the presenter and the information he shared.
"Confidence is at the core of the relationship between a broadcaster and its audience, especially for a public service broadcaster such as the BBC.
"This oversight had the potential to damage the significantly high levels of trust that viewers would have placed in a BBC factual programme about the Israel-Gaza war."
The programme was pulled from the BBC's streaming service in last February after the narrator's familial connections emerged, and in the month of July an corporation's own inquiry determined it infringed the broadcaster's content policies on factual correctness.
A corporation official commented: "The Ofcom ruling is in line with the results of the corporation's inquiry, that there was a significant failing in the programme in relation to the broadcaster's journalistic policies on truthfulness, which reflects clause 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we accept the authority's determination in its entirety. We will adhere to the directive as soon as the schedule and wording are finalised."
