The public service broadcaster committed a "major breach" of broadcasting rules by omitting to mention that the presenter of a programme about the Gaza situation was the offspring of a Hamas official, according to British broadcasting authority Ofcom.
An probe by Ofcom into Gaza: How to Survive a Warzone has determined that the film was "materially misleading".
The BBC's director general had already issued an apology, stating there had been "a major oversight in relation to accuracy".
The authority has directed the BBC to transmit a prime-time declaration about its decisions.
"Given this constitutes a major infringement of our regulations, we are instructing the broadcaster to air a message of our determinations against it on BBC2 at 21:00, with a timing to be confirmed," it said.
'Risk to Undermine Confidence'
The authority's announcement declared: "Our probe concluded that the documentary's omission to reveal that the narrator's parent held a role in the Hamas-run government was substantially inaccurate.
"Consequently that the audience did not have critical information which may have been very significant to their judgment of the voice and the content he provided.
"Confidence is at the core of the connection between a media organization and its viewers, especially for a public service broadcaster such as the public broadcaster.
"This failing had the possibility to undermine the very considerable levels of confidence that the public would have invested in a factual film from the broadcaster about the Gaza conflict."
The documentary was removed from iPlayer in last February after the presenter's family links emerged, and in this past July an corporation's own inquiry determined it breached the organization's editorial guidelines on truthfulness.
A representative for the broadcaster commented: "The authority's determination is in accordance with the conclusions of the corporation's inquiry, that there was a serious error in the programme in relation to the broadcaster's journalistic policies on factual correctness, which reflects regulation 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we agree with the authority's determination in its entirety. We will follow the directive as soon as the date and wording are determined."
