The British broadcaster engaged in a "serious breach" of industry standards by not revealing that the presenter of a programme about the Gaza situation was the son of a Hamas administrator, as ruled by regulatory body Ofcom.
An inquiry by Ofcom into Gaza: How to Survive a Warzone has found that the programme was "significantly deceptive".
The head of the BBC had already issued an apology, noting there had been "a significant failing in relation to accuracy".
Ofcom has ordered the BBC to broadcast a prime-time declaration about its findings.
"As this represents a major infringement of our code, we are directing the BBC to air a announcement of our determinations against it on BBC2 at 21:00, with a date to be finalised," the regulator stated.
'Risk to Damage Trust'
The regulator's announcement said: "The inquiry we conducted concluded that the documentary's omission to reveal that the presenter's father served in a position in the Hamas-controlled administration was materially misleading.
"Consequently that the audience did not have critical information which may have been highly relevant to their judgment of the presenter and the content he presented.
"Trust is at the center of the bond between a broadcaster and its viewers, particularly for a public service broadcaster such as the BBC.
"This oversight had the possibility to damage the significantly high amounts of credibility that viewers would have put in a BBC factual programme about the Israel-Gaza war."
The programme was removed from iPlayer in the month of February after the presenter's familial connections came to light, and in this past July an broadcaster's internal assessment found it infringed the broadcaster's content policies on factual correctness.
A BBC spokesperson said: "The authority's determination is in accordance with the findings of Peter Johnston's review, that there was a serious error in the film in relation to the broadcaster's journalistic policies on truthfulness, which reflects regulation 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we comply with the authority's determination in its entirety. We will comply with the directive as soon as the schedule and wording are determined."
