The public service broadcaster committed a "significant breach" of broadcasting rules by omitting to mention that the presenter of a film about the Gaza conflict was the child of a Hamas official, as ruled by British broadcasting authority Ofcom.
An inquiry by the broadcasting watchdog into the programme Gaza: How to Survive a Warzone has concluded that the film was "significantly deceptive".
The chief executive of the broadcaster had already issued an apology, saying there had been "a serious error in relation to factual correctness".
Ofcom has instructed the corporation to air a prime-time announcement about its conclusions.
"Since this amounts to a significant violation of our rules, we are instructing the BBC to broadcast a announcement of our findings against it on BBC2 at 21:00, with a timing to be finalised," it said.
'Potential to Undermine Credibility'
The watchdog's report declared: "The inquiry we conducted concluded that the programme's failure to disclose that the narrator's father occupied a role in the Hamas-controlled government was significantly deceptive.
"Consequently that the viewers did not have vital facts which may have been very significant to their evaluation of the voice and the content he provided.
"Credibility is at the core of the bond between a media organization and its viewers, notably for a state-funded media outlet such as the public broadcaster.
"This oversight had the potential to erode the very considerable levels of trust that the public would have put in a factual film from the broadcaster about the Israel-Gaza war."
The programme was pulled from iPlayer in the month of February after the presenter's family links came to light, and in the month of July an internal BBC review concluded it breached the broadcaster's journalistic standards on truthfulness.
A corporation official stated: "The Ofcom ruling is in line with the results of Peter Johnston's review, that there was a serious error in the programme in relation to the BBC's Editorial Guidelines on factual correctness, which aligns with clause 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we comply with the regulator's ruling in its entirety. We will follow the sanction as soon as the timing and wording are confirmed."
