The British broadcaster was found to have committed a "major breach" of media regulations by omitting to mention that the narrator of a documentary about the Gaza conflict was the child of a Hamas administrator, as determined by British broadcasting authority Ofcom.
An probe by the media regulator into Gaza: How to Survive a Warzone has found that the documentary was "materially misleading".
The BBC's director general had already issued an apology, stating there had been "a significant failing in relation to accuracy".
Ofcom has instructed the corporation to broadcast a prime-time announcement about its findings.
"Since this amounts to a major infringement of our regulations, we are ordering the corporation to transmit a announcement of our conclusions against it on BBC2 at 9pm, with a timing to be determined," it said.
'Possibility to Erode Credibility'
The watchdog's report declared: "The inquiry we conducted determined that the programme's lack of disclosure that the voice's male guardian served in a role in the Hamas-administered authority was significantly deceptive.
"It meant that the viewers did not have critical information which may have been very significant to their evaluation of the voice and the details he presented.
"Trust is at the core of the bond between a media organization and its public, especially for a national broadcasting corporation such as the public broadcaster.
"This error had the possibility to erode the significantly high levels of trust that viewers would have placed in a documentary produced by the BBC about the conflict in Gaza."
The documentary was withdrawn from the BBC's streaming service in last February after the boy's familial connections were revealed, and in July an corporation's own inquiry concluded it breached the corporation's journalistic standards on factual correctness.
A representative for the broadcaster said: "The authority's determination is in line with the conclusions of the internal assessment, that there was a significant failing in the programme in relation to the BBC's Editorial Guidelines on factual correctness, which corresponds to clause 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we agree with the regulator's ruling in full. We will adhere to the penalty as soon as the timing and wording are determined."
