The public service broadcaster committed a "significant breach" of industry standards by omitting to mention that the presenter of a film about the Gaza conflict was the child of a Hamas representative, as ruled by UK media regulator Ofcom.
An investigation by Ofcom into Gaza: How to Survive a Warzone has determined that the film was "substantially inaccurate".
The BBC's director general had earlier expressed regret, stating there had been "a serious error in relation to truthfulness".
The regulator has instructed the broadcaster to air a peak-time statement about its conclusions.
"As this represents a significant violation of our regulations, we are directing the corporation to air a message of our findings against it on the BBC's second channel at 9pm, with a schedule to be determined," the statement read.
'Risk to Erode Credibility'
The watchdog's report declared: "The inquiry we conducted concluded that the programme's lack of disclosure that the narrator's parent held a position in the Hamas-controlled government was materially misleading.
"Consequently that the public did not have essential details which may have been extremely pertinent to their evaluation of the presenter and the information he provided.
"Confidence is at the heart of the bond between a media organization and its viewers, particularly for a state-funded media outlet such as the public broadcaster.
"This failing had the risk to erode the exceptionally strong levels of credibility that the public would have put in a documentary produced by the BBC about the Israel-Gaza war."
The documentary was removed from iPlayer in February after the boy's family links were revealed, and in July an corporation's own inquiry concluded it violated the broadcaster's editorial guidelines on truthfulness.
A BBC spokesperson commented: "The authority's determination is in accordance with the findings of the corporation's inquiry, that there was a major oversight in the programme in relation to the BBC's Editorial Guidelines on factual correctness, which aligns with Rule 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we comply with Ofcom's decision in complete. We will adhere to the penalty as soon as the date and wording are finalised."
