The BBC engaged in a "serious breach" of industry standards by omitting to mention that the narrator of a programme about the Gaza conflict was the child of a Hamas administrator, according to regulatory body Ofcom.
An investigation by Ofcom into the documentary titled Gaza: How to Survive a Warzone has concluded that the programme was "substantially inaccurate".
The head of the BBC had already issued an apology, noting there had been "a serious error in relation to truthfulness".
Ofcom has instructed the corporation to broadcast a prime-time declaration about its conclusions.
"As this represents a significant violation of our regulations, we are directing the BBC to air a statement of our conclusions against it on BBC2 at 21:00, with a date to be confirmed," the statement read.
'Potential to Damage Trust'
The regulator's report stated: "Our probe found that the documentary's lack of disclosure that the narrator's male guardian served in a role in the Hamas-run authority was substantially inaccurate.
"Consequently that the audience did not have critical information which may have been extremely pertinent to their evaluation of the voice and the information he presented.
"Credibility is at the heart of the relationship between a television network and its viewers, notably for a national broadcasting corporation such as the British Broadcasting Corporation.
"This failing had the risk to damage the exceptionally strong levels of confidence that viewers would have placed in a documentary produced by the BBC about the Israel-Gaza war."
The documentary was pulled from iPlayer in last February after the presenter's family links came to light, and in July an corporation's own inquiry determined it breached the corporation's content policies on truthfulness.
A BBC spokesperson stated: "The regulator's decision is in line with the results of the internal assessment, that there was a major oversight in the film in relation to the corporation's content standards on factual correctness, which corresponds to clause 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 adhere to the penalty as soon as the date and language are determined."
