The BBC committed a "major breach" of industry standards by omitting to mention that the narrator of a film about Gaza was the offspring of a Hamas representative, as determined by regulatory body Ofcom.
An inquiry by the media regulator into the documentary titled Gaza: How to Survive a Warzone has determined that the documentary was "significantly deceptive".
The BBC's director general had earlier expressed regret, saying there had been "a serious error in relation to factual correctness".
Ofcom has directed the corporation to air a evening declaration about its findings.
"Given this constitutes a major infringement of our rules, we are ordering the BBC to transmit a message of our findings against it on BBC Two at 21:00, with a date to be confirmed," the regulator stated.
'Risk to Damage Credibility'
The watchdog's report stated: "Our investigation concluded that the film's omission to reveal that the voice's male guardian occupied a post in the Hamas-administered administration was significantly deceptive.
"It meant that the public did not have vital facts which may have been very significant to their judgment of the narrator and the details he shared.
"Credibility is at the core of the bond between a television network and its viewers, especially for a national broadcasting corporation such as the public broadcaster.
"This error had the possibility to undermine the significantly high degrees of credibility that viewers would have put in a BBC factual programme about the Gaza conflict."
The programme was withdrawn from the BBC's streaming service in February after the boy's familial connections emerged, and in July an corporation's own inquiry found it violated the organization's journalistic standards on accuracy.
A representative for the broadcaster commented: "The Ofcom ruling is in line with the findings of Peter Johnston's review, that there was a serious error in the film in relation to the broadcaster's journalistic policies on accuracy, which corresponds to regulation 2.2 of the regulator's media standards.
"We issued an apology for this and we accept Ofcom's decision in its entirety. We will adhere to the penalty as soon as the date and wording are finalised."
