The British broadcaster was found to have committed a "significant breach" of industry standards by failing to disclose that the presenter of a film about the Gaza situation was the son of a Hamas administrator, according to British broadcasting authority Ofcom.
An probe by Ofcom into the documentary titled Gaza: How to Survive a Warzone has determined that the documentary was "significantly deceptive".
The BBC's director general had already issued an apology, saying there had been "a major oversight in relation to accuracy".
Ofcom has ordered the BBC to air a evening declaration about its findings.
"Given this constitutes a major infringement of our regulations, we are ordering the broadcaster to broadcast a announcement of our conclusions against it on BBC2 at 21:00, with a timing to be confirmed," it said.
'Risk to Undermine Confidence'
The authority's statement said: "Our investigation concluded that the documentary's omission to reveal that the narrator's parent held a role in the Hamas-run administration was significantly deceptive.
"This implied that the audience did not have vital facts which may have been extremely pertinent to their assessment of the voice and the content he presented.
"Confidence is at the heart of the connection between a media organization and its audience, especially for a state-funded media outlet such as the BBC.
"This failing had the potential to damage the very considerable degrees of confidence that audiences would have put in a factual film from the broadcaster about the Israel-Gaza war."
The programme was withdrawn from the BBC's streaming service in the month of February after the presenter's familial connections came to light, and in July an internal BBC review determined it violated the organization's journalistic standards on factual correctness.
A BBC spokesperson stated: "The Ofcom ruling is in agreement with the results of Peter Johnston's review, that there was a major oversight in the programme in relation to the broadcaster's journalistic policies on truthfulness, which reflects Rule 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we agree with the authority's determination in full. We will follow the sanction as soon as the timing and wording are determined."
