The BBC was found to have committed a "significant breach" of broadcasting rules by failing to disclose that the presenter of a programme about Gaza was the child of a Hamas administrator, as determined by regulatory body Ofcom.
An probe by the broadcasting watchdog into the programme Gaza: How to Survive a Warzone has determined that the programme was "substantially inaccurate".
The BBC's director general had already issued an apology, saying there had been "a serious error in relation to accuracy".
Ofcom has instructed the BBC to broadcast a prime-time statement about its findings.
"As this represents a significant violation of our rules, we are instructing the BBC to transmit a message of our determinations against it on BBC Two at 21:00, with a schedule to be determined," it said.
'Risk to Damage Confidence'
The authority's announcement stated: "The inquiry we conducted determined that the documentary's lack of disclosure that the presenter's male guardian occupied a position in the Hamas-administered authority was significantly deceptive.
"Consequently that the audience did not have vital facts which may have been very significant to their assessment of the presenter and the details he presented.
"Credibility is at the core of the connection between a television network and its public, especially for a national broadcasting corporation such as the public broadcaster.
"This oversight had the possibility to erode the very considerable degrees of confidence that the public would have invested in a documentary produced by the BBC about the conflict in Gaza."
The film was pulled from iPlayer in February after the narrator's family links emerged, and in this past July an corporation's own inquiry concluded it violated the organization's editorial guidelines on factual correctness.
A corporation official stated: "The authority's determination is in line with the findings of Peter Johnston's review, that there was a serious error in the film in relation to the BBC's Editorial Guidelines on truthfulness, which aligns with regulation 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we agree with the authority's determination in complete. We will comply with the sanction as soon as the date and wording are determined."
