The BBC engaged in a "serious breach" of media regulations by not revealing that the presenter of a documentary about Gaza was the child of a Hamas official, according to UK media regulator Ofcom.
An investigation by the broadcasting watchdog into Gaza: How to Survive a Warzone has found that the programme was "substantially inaccurate".
The chief executive of the broadcaster had previously apologised, stating there had been "a serious error in relation to accuracy".
The regulator has instructed the corporation to transmit a evening announcement about its conclusions.
"As this represents a major infringement of our code, we are ordering the corporation to broadcast a statement of our findings against it on the BBC's second channel at 9pm, with a timing to be determined," the statement read.
'Risk to Damage Confidence'
The authority's announcement said: "Our probe determined that the film's omission to reveal that the voice's male guardian served in a role in the Hamas-run authority was materially misleading.
"It meant that the audience did not have vital facts which may have been highly relevant to their evaluation of the narrator and the information he presented.
"Credibility is at the heart of the bond between a broadcaster and its public, notably for a national broadcasting corporation such as the British Broadcasting Corporation.
"This failing had the risk to erode the significantly high levels of credibility that viewers would have placed in a documentary produced by the BBC about the Gaza conflict."
The film was removed from iPlayer in February after the boy's personal associations came to light, and in July an corporation's own inquiry concluded it violated the organization's journalistic standards on factual correctness.
A representative for the broadcaster said: "The Ofcom ruling is in line with the results of the corporation's inquiry, that there was a major oversight in the film in relation to the BBC's Editorial Guidelines on accuracy, which corresponds to regulation 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we comply with the regulator's ruling in its entirety. We will follow the penalty as soon as the date and language are confirmed."
