The public service broadcaster was found to have committed a "major breach" of industry standards by omitting to mention that the narrator of a programme about the Gaza conflict was the child of a Hamas administrator, as ruled by UK media regulator Ofcom.
An investigation by the broadcasting watchdog into the programme Gaza: How to Survive a Warzone has concluded that the programme was "materially misleading".
The BBC's director general had already issued an apology, stating there had been "a serious error in relation to factual correctness".
The authority has directed the BBC to air a peak-time declaration about its findings.
"As this represents a significant violation of our code, we are directing the broadcaster to broadcast a message of our conclusions against it on the BBC's second channel at 21:00, with a timing to be confirmed," it said.
'Risk to Damage Confidence'
The watchdog's announcement said: "The inquiry we conducted found that the film's lack of disclosure that the narrator's parent served in a position in the Hamas-administered administration was significantly deceptive.
"Consequently that the viewers did not have essential details which may have been very significant to their evaluation of the narrator and the information he provided.
"Confidence is at the core of the relationship between a television network and its public, notably for a state-funded media outlet such as the British Broadcasting Corporation.
"This failing had the potential to undermine the significantly high amounts of credibility that audiences would have invested in a documentary produced by the BBC about the Israel-Gaza war."
The programme was removed from iPlayer in February after the boy's personal associations emerged, and in this past July an broadcaster's internal assessment found it breached the corporation's journalistic standards on accuracy.
A representative for the broadcaster said: "The Ofcom ruling is in agreement with the results of the internal assessment, that there was a serious error in the documentary in relation to the broadcaster's journalistic policies on factual correctness, which reflects clause 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we accept the authority's determination in complete. We will comply with the penalty as soon as the timing and wording are finalised."
