The British broadcaster committed a "serious breach" of media regulations by failing to disclose that the narrator of a programme about Gaza was the child of a Hamas administrator, as ruled by UK media regulator Ofcom.
An probe by the broadcasting watchdog into Gaza: How to Survive a Warzone has determined that the programme was "materially misleading".
The BBC's director general had previously apologised, saying there had been "a significant failing in relation to accuracy".
The regulator has ordered the BBC to broadcast a prime-time announcement about its decisions.
"As this represents a serious breach of our rules, we are directing the corporation to air a message of our conclusions against it on BBC2 at 21:00, with a timing to be finalised," it said.
'Potential to Undermine Confidence'
The authority's report declared: "Our investigation determined that the programme's failure to disclose that the voice's parent occupied a post in the Hamas-run authority was substantially inaccurate.
"Consequently that the viewers did not have vital facts which may have been extremely pertinent to their judgment of the narrator and the information he provided.
"Credibility is at the core of the relationship between a broadcaster and its viewers, notably for a public service broadcaster such as the public broadcaster.
"This oversight had the possibility to undermine the significantly high amounts of trust that the public would have invested in a factual film from the broadcaster about the Israel-Gaza war."
The programme was removed from the BBC's streaming service in February after the presenter's family links came to light, and in this past July an broadcaster's internal assessment found it breached the broadcaster's content policies on accuracy.
A representative for the broadcaster said: "The authority's determination is in line with the findings of Peter Johnston's review, that there was a significant failing in the documentary in relation to the broadcaster's journalistic policies on accuracy, which aligns with regulation 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we comply with the regulator's ruling in full. We will follow the directive as soon as the timing and language are finalised."
