The BBC engaged in a "significant breach" of media regulations by omitting to mention that the narrator of a film about the Gaza situation was the son of a Hamas representative, as determined by regulatory body Ofcom.
An inquiry by Ofcom into the documentary titled Gaza: How to Survive a Warzone has determined that the film was "significantly deceptive".
The BBC's director general had earlier expressed regret, stating there had been "a significant failing in relation to factual correctness".
Ofcom has ordered the broadcaster to broadcast a peak-time declaration about its conclusions.
"Since this amounts to a major infringement of our code, we are ordering the broadcaster to broadcast a message of our determinations against it on the BBC's second channel at 9pm, with a timing to be finalised," it said.
'Potential to Undermine Confidence'
The authority's statement declared: "Our probe determined that the programme's omission to reveal that the voice's father held a role in the Hamas-controlled government was significantly deceptive.
"Consequently that the viewers did not have critical information which may have been extremely pertinent to their evaluation of the presenter and the details he presented.
"Confidence is at the center of the connection between a television network and its viewers, especially for a state-funded media outlet such as the public broadcaster.
"This oversight had the risk to undermine the very considerable degrees of credibility that the public would have invested in a documentary produced by the BBC about the Gaza conflict."
The documentary was withdrawn from the BBC's streaming service in February after the narrator's personal associations were revealed, and in this past July an internal BBC review determined it breached the organization's content policies on factual correctness.
A BBC spokesperson said: "The authority's determination is in accordance with the results of the internal assessment, that there was a serious error in the documentary in relation to the broadcaster's journalistic policies on factual correctness, which corresponds to clause 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we agree with the regulator's ruling in full. We will follow the penalty as soon as the date and wording are confirmed."
