The BBC engaged in a "serious breach" of industry standards by not revealing that the narrator of a documentary about Gaza was the son of a Hamas official, according to regulatory body Ofcom.
An investigation by the broadcasting watchdog into Gaza: How to Survive a Warzone has concluded that the film was "substantially inaccurate".
The chief executive of the broadcaster had earlier expressed regret, saying there had been "a major oversight in relation to factual correctness".
The authority has directed the broadcaster to broadcast a evening announcement about its decisions.
"As this represents a significant violation of our regulations, we are instructing the corporation to broadcast a statement of our findings against it on the BBC's second channel at 9pm, with a date to be finalised," the statement read.
'Possibility to Erode Credibility'
The regulator's statement declared: "Our probe found that the programme's failure to disclose that the narrator's father held a role in the Hamas-run authority was materially misleading.
"Consequently that the public did not have essential details which may have been extremely pertinent to their assessment of the narrator and the content he shared.
"Trust is at the center of the relationship between a broadcaster and its viewers, notably for a public service broadcaster such as the BBC.
"This oversight had the risk to damage the exceptionally strong degrees of credibility that viewers would have placed in a factual film from the broadcaster about the Gaza conflict."
The film was pulled from the online platform in February after the boy's personal associations emerged, and in the month of July an corporation's own inquiry concluded it infringed the broadcaster's journalistic standards on accuracy.
A BBC spokesperson said: "The Ofcom ruling is in agreement with the conclusions of the internal assessment, that there was a major oversight in the programme in relation to the broadcaster's journalistic policies on factual correctness, which reflects Rule 2.2 of the regulator's media standards.
"We issued an apology for this and we agree with the regulator's ruling in its entirety. We will adhere to the sanction as soon as the schedule and language are finalised."
