The British broadcaster engaged in a "major breach" of media regulations by omitting to mention that the presenter of a programme about Gaza was the offspring of a Hamas administrator, as determined by UK media regulator Ofcom.
An investigation by Ofcom into the programme Gaza: How to Survive a Warzone has found that the programme was "significantly deceptive".
The BBC's director general had already issued an apology, stating there had been "a serious error in relation to accuracy".
The authority has ordered the BBC to transmit a prime-time statement about its findings.
"Given this constitutes a significant violation of our rules, we are instructing the corporation to air a message of our determinations against it on BBC2 at 9pm, with a timing to be finalised," it said.
'Possibility to Undermine Confidence'
The watchdog's statement stated: "Our investigation found that the documentary's failure to disclose that the narrator's parent occupied a post in the Hamas-run authority was substantially inaccurate.
"Consequently that the viewers did not have essential details which may have been highly relevant to their assessment of the presenter and the content he presented.
"Trust is at the core of the connection between a media organization and its public, especially for a public service broadcaster such as the BBC.
"This oversight had the risk to undermine the very considerable levels of trust that viewers would have placed in a BBC factual programme about the conflict in Gaza."
The programme was pulled from iPlayer in February after the narrator's familial connections came to light, and in July an internal BBC review found it breached the organization's content policies on truthfulness.
A BBC spokesperson said: "The Ofcom ruling is in agreement with the conclusions of the corporation's inquiry, that there was a significant failing in the film in relation to the broadcaster's journalistic policies on accuracy, which reflects regulation 2.2 of the regulator's media standards.
"We expressed regret for this and we agree with the regulator's ruling in complete. We will follow the directive as soon as the timing and wording are finalised."
