The British broadcaster committed a "serious breach" of broadcasting rules by failing to disclose that the presenter of a film about Gaza was the son of a Hamas representative, according to regulatory body Ofcom.
An probe by the broadcasting watchdog into Gaza: How to Survive a Warzone has determined that the programme was "substantially inaccurate".
The BBC's director general had earlier expressed regret, saying there had been "a major oversight in relation to truthfulness".
The regulator has instructed the broadcaster to transmit a evening statement about its findings.
"Since this amounts to a serious breach of our rules, we are directing the BBC to air a statement of our conclusions against it on BBC2 at 21:00, with a timing to be confirmed," the statement read.
'Risk to Damage Credibility'
The authority's statement stated: "Our investigation concluded that the film's failure to disclose that the voice's male guardian occupied a role in the Hamas-run government was materially misleading.
"Consequently that the public did not have essential details which may have been extremely pertinent to their assessment of the presenter and the details he presented.
"Trust is at the heart of the bond between a media organization and its public, especially for a national broadcasting corporation such as the BBC.
"This error had the potential to undermine the exceptionally strong levels of trust that audiences would have put in a factual film from the broadcaster about the Gaza conflict."
The documentary was removed from the BBC's streaming service in February after the narrator's familial connections were revealed, and in this past July an corporation's own inquiry found it infringed the organization's editorial guidelines on accuracy.
A representative for the broadcaster said: "The regulator's decision is in line with the findings of Peter Johnston's review, that there was a major oversight in the documentary in relation to the broadcaster's journalistic policies on accuracy, which aligns with regulation 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we comply with the regulator's ruling in its entirety. We will follow the penalty as soon as the schedule and language are finalised."
