The BBC was found to have committed a "significant breach" of broadcasting rules by omitting to mention that the voice of a programme about the Gaza situation was the offspring of a Hamas administrator, according to British broadcasting authority Ofcom.
An inquiry by the broadcasting watchdog into the programme Gaza: How to Survive a Warzone has concluded that the film was "significantly deceptive".
The BBC's director general had earlier expressed regret, stating there had been "a serious error in relation to truthfulness".
Ofcom has ordered the corporation to air a peak-time declaration about its conclusions.
"As this represents a significant violation of our rules, we are directing the broadcaster to broadcast a statement of our conclusions against it on BBC Two at 21:00, with a timing to be finalised," the statement read.
'Risk to Undermine Trust'
The watchdog's announcement said: "Our probe found that the documentary's failure to disclose that the voice's father served in a post in the Hamas-administered authority was substantially inaccurate.
"Consequently that the public did not have essential details which may have been highly relevant to their assessment of the narrator and the information he provided.
"Trust is at the core of the connection between a television network and its audience, particularly for a state-funded media outlet such as the British Broadcasting Corporation.
"This oversight had the risk to erode the significantly high degrees of credibility that viewers would have invested in a factual film from the broadcaster about the conflict in Gaza."
The programme was withdrawn from the online platform in February after the narrator's familial connections emerged, and in the month of July an broadcaster's internal assessment concluded it breached the organization's journalistic standards on truthfulness.
A BBC spokesperson said: "The regulator's decision is in line with the results of Peter Johnston's review, that there was a significant failing in the programme in relation to the broadcaster's journalistic policies on factual correctness, which aligns with Rule 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we comply with the authority's determination in full. We will follow the sanction as soon as the date and language are finalised."
