The British broadcaster was found to have 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 ruled by regulatory body Ofcom.
An inquiry by the broadcasting watchdog into the programme Gaza: How to Survive a Warzone has found that the documentary was "significantly deceptive".
The BBC's director general had earlier expressed regret, noting there had been "a major oversight in relation to factual correctness".
The regulator has instructed the corporation to broadcast a evening announcement about its findings.
"Since this amounts to a major infringement of our regulations, we are directing the broadcaster to air a announcement of our conclusions against it on BBC2 at 9pm, with a timing to be confirmed," the regulator stated.
'Potential to Undermine Confidence'
The authority's statement stated: "Our investigation determined that the programme's omission to reveal that the voice's parent served in a post in the Hamas-run authority was significantly deceptive.
"Consequently that the viewers did not have vital facts which may have been highly relevant to their evaluation of the voice and the details he provided.
"Credibility is at the heart of the relationship between a media organization and its viewers, notably for a state-funded media outlet such as the British Broadcasting Corporation.
"This error had the risk to erode the very considerable levels of confidence that audiences would have placed in a factual film from the broadcaster about the Gaza conflict."
The film was removed from the BBC's streaming service in last February after the boy's personal associations emerged, and in July an corporation's own inquiry determined it infringed the broadcaster's content policies on factual correctness.
A corporation official stated: "The Ofcom ruling is in line with the results of Peter Johnston's review, that there was a major oversight in the documentary in relation to the BBC's Editorial Guidelines on truthfulness, which aligns with regulation 2.2 of Ofcom's Broadcasting Code.
"We have apologised 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."
