The BBC engaged in a "major breach" of industry standards by failing to disclose that the narrator of a documentary about the Gaza situation was the offspring of a Hamas administrator, as ruled by UK media regulator Ofcom.
An inquiry by the broadcasting watchdog into Gaza: How to Survive a Warzone has found that the film was "substantially inaccurate".
The BBC's director general had earlier expressed regret, noting there had been "a significant failing in relation to factual correctness".
The authority has ordered the broadcaster to air a peak-time statement about its conclusions.
"As this represents a serious breach of our code, we are ordering the BBC to air a message of our findings against it on BBC2 at 9pm, with a schedule to be finalised," it said.
'Possibility to Damage Trust'
The authority's statement said: "Our investigation found that the programme's omission to reveal that the narrator's male guardian held a position in the Hamas-controlled government was substantially inaccurate.
"This implied that the viewers did not have essential details which may have been very significant to their evaluation of the presenter and the content he presented.
"Trust is at the core of the bond between a broadcaster and its viewers, particularly for a state-funded media outlet such as the BBC.
"This oversight had the potential to damage the exceptionally strong levels of trust that the public would have invested in a documentary produced by the BBC about the conflict in Gaza."
The film was withdrawn from the BBC's streaming service in the month of February after the presenter's personal associations came to light, and in this past July an internal BBC review found it violated the broadcaster's content policies on truthfulness.
A representative for the broadcaster said: "The regulator's decision is in agreement with the findings of the corporation's inquiry, that there was a major oversight in the programme in relation to the corporation's content standards on accuracy, which reflects regulation 2.2 of the authority's broadcasting regulations.
"We have apologised for this and we comply with the authority's determination in its entirety. We will follow the directive as soon as the schedule and wording are confirmed."
