The BBC was found to have committed a "significant breach" of broadcasting rules by failing to disclose that the presenter of a documentary about Gaza was the son of a Hamas official, as determined by regulatory body Ofcom.
An investigation by the media regulator into Gaza: How to Survive a Warzone has determined that the documentary was "materially misleading".
The BBC's director general had earlier expressed regret, saying there had been "a serious error in relation to factual correctness".
The authority has ordered the BBC to broadcast a peak-time announcement about its decisions.
"Given this constitutes a major infringement of our code, we are ordering the corporation to transmit a announcement of our conclusions against it on the BBC's second channel at 21:00, with a timing to be confirmed," the regulator stated.
'Risk to Damage Confidence'
The watchdog's announcement stated: "Our investigation concluded that the programme's lack of disclosure that the narrator's male guardian occupied a position in the Hamas-run government was materially misleading.
"This implied that the viewers did not have critical information which may have been highly relevant to their judgment of the voice and the information he shared.
"Confidence is at the center of the connection between a television network and its viewers, especially for a national broadcasting corporation such as the British Broadcasting Corporation.
"This oversight had the potential to erode the very considerable degrees of confidence that the public would have put in a documentary produced by the BBC about the Gaza conflict."
The programme was withdrawn from the online platform in February after the boy's familial connections emerged, and in July an corporation's own inquiry concluded it infringed the organization's journalistic standards on truthfulness.
A representative for the broadcaster said: "The regulator's decision is in accordance with the conclusions of the corporation's inquiry, that there was a major oversight in the documentary in relation to the corporation's content standards on factual correctness, which reflects Rule 2.2 of the regulator's media standards.
"We issued an apology for this and we accept the authority's determination in complete. We will comply with the penalty as soon as the schedule and language are finalised."
