The BBC engaged in a "major breach" of media regulations by failing to disclose that the presenter of a film about the Gaza conflict was the son of a Hamas representative, as ruled by UK media regulator Ofcom.
An inquiry by Ofcom into Gaza: How to Survive a Warzone has concluded that the film was "substantially inaccurate".
The BBC's director general had previously apologised, stating there had been "a major oversight in relation to accuracy".
The authority has directed the corporation to transmit a evening statement about its findings.
"Given this constitutes a serious breach of our rules, we are ordering the corporation to air a message of our determinations against it on BBC2 at nine o'clock in the evening, with a timing to be finalised," it said.
'Risk to Damage Trust'
The watchdog's statement declared: "Our investigation concluded that the documentary's failure to disclose that the presenter's parent served in a post in the Hamas-run administration was substantially inaccurate.
"This implied that the public did not have essential details which may have been very significant to their judgment of the voice and the content he shared.
"Credibility is at the heart of the relationship between a media organization and its viewers, especially for a state-funded media outlet such as the British Broadcasting Corporation.
"This failing had the risk to undermine the significantly high levels of credibility that viewers would have placed in a BBC factual programme about the Gaza conflict."
The programme was removed from the online platform in February after the narrator's familial connections emerged, and in this past July an corporation's own inquiry concluded it violated the broadcaster's editorial guidelines on truthfulness.
A corporation official stated: "The regulator's decision is in agreement with the results of Peter Johnston's review, that there was a major oversight in the documentary in relation to the broadcaster's journalistic policies on factual correctness, which aligns with regulation 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we agree with the regulator's ruling in its entirety. We will follow the penalty as soon as the schedule and language are confirmed."
