The BBC engaged in a "serious breach" of industry standards by omitting to mention that the voice of a film about the Gaza situation was the offspring of a Hamas representative, as determined by UK media regulator Ofcom.
An inquiry by the media regulator into the programme Gaza: How to Survive a Warzone has concluded that the programme was "materially misleading".
The BBC's director general had previously apologised, saying there had been "a serious error in relation to factual correctness".
Ofcom has ordered the broadcaster to air a prime-time announcement about its conclusions.
"Since this amounts to a serious breach of our code, we are instructing the BBC to air a message of our conclusions against it on BBC Two at 9pm, with a schedule to be confirmed," it said.
'Potential to Damage Confidence'
The regulator's report said: "The inquiry we conducted concluded that the film's omission to reveal that the narrator's male guardian occupied a post in the Hamas-run administration was materially misleading.
"It meant that the public did not have vital facts which may have been very significant to their evaluation of the presenter and the details he presented.
"Credibility is at the heart of the relationship between a television network and its viewers, particularly for a national broadcasting corporation such as the BBC.
"This failing had the risk to damage the very considerable amounts of trust that viewers would have placed in a BBC factual programme about the conflict in Gaza."
The film was removed from iPlayer in February after the boy's personal associations were revealed, and in the month of July an corporation's own inquiry found it violated the corporation's editorial guidelines on accuracy.
A BBC spokesperson stated: "The authority's determination is in agreement with the conclusions of the internal assessment, that there was a major oversight in the programme in relation to the BBC's Editorial Guidelines on truthfulness, which reflects clause 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we accept the authority's determination in full. We will adhere to the penalty as soon as the date and wording are finalised."
