The BBC was found to have committed a "serious breach" of broadcasting rules by omitting to mention that the narrator of a documentary about Gaza was the offspring of a Hamas administrator, as ruled by regulatory body Ofcom.
An investigation by the media regulator into the documentary titled Gaza: How to Survive a Warzone has concluded that the programme was "materially misleading".
The chief executive of the broadcaster had already issued an apology, saying there had been "a serious error in relation to accuracy".
Ofcom has instructed the broadcaster to air a evening announcement about its findings.
"Since this amounts to a major infringement of our regulations, we are ordering the broadcaster to broadcast a announcement of our findings against it on BBC Two at nine o'clock in the evening, with a date to be finalised," it said.
'Potential to Damage Trust'
The authority's announcement stated: "Our investigation concluded that the film's lack of disclosure that the voice's parent occupied a position in the Hamas-run authority was significantly deceptive.
"Consequently that the audience did not have vital facts which may have been highly relevant to their judgment of the narrator and the details he provided.
"Trust is at the center of the bond between a media organization and its viewers, especially for a public service broadcaster such as the public broadcaster.
"This error had the risk to erode the exceptionally strong degrees of confidence that the public would have placed in a BBC factual programme about the conflict in Gaza."
The programme was withdrawn from the BBC's streaming service in February after the boy's family links were revealed, and in the month of July an corporation's own inquiry found it infringed the broadcaster's content policies on factual correctness.
A representative for the broadcaster said: "The authority's determination is in line with the findings of the corporation's inquiry, that there was a significant failing in the programme in relation to the broadcaster's journalistic policies on truthfulness, which aligns with clause 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we accept the regulator's ruling in full. We will comply with the penalty as soon as the timing and wording are finalised."
