The BBC committed a "serious breach" of industry standards by omitting to mention that the narrator of a programme about the Gaza situation was the child of a Hamas representative, according to UK media regulator Ofcom.
An inquiry by Ofcom into Gaza: How to Survive a Warzone has determined that the programme was "significantly deceptive".
The BBC's director general had earlier expressed regret, saying there had been "a serious error in relation to accuracy".
The authority has directed the BBC to broadcast a peak-time declaration about its decisions.
"Since this amounts to a major infringement of our regulations, we are directing the corporation to air a announcement of our determinations against it on BBC Two at 21:00, with a timing to be confirmed," the regulator stated.
'Potential to Undermine Credibility'
The authority's statement said: "The inquiry we conducted found that the film's omission to reveal that the voice's parent held a role in the Hamas-run authority was significantly deceptive.
"Consequently that the viewers did not have critical information which may have been extremely pertinent to their judgment of the presenter and the content he presented.
"Confidence is at the center of the connection between a media organization and its public, notably for a national broadcasting corporation such as the BBC.
"This error had the potential to erode the exceptionally strong levels of credibility that audiences would have put in a documentary produced by the BBC about the Israel-Gaza war."
The film was pulled from the BBC's streaming service in last February after the boy's familial connections came to light, and in the month of July an corporation's own inquiry concluded it violated the corporation's content policies on factual correctness.
A BBC spokesperson said: "The regulator's decision is in line with the results of the corporation's inquiry, that there was a major oversight in the documentary in relation to the broadcaster's journalistic policies on factual correctness, which corresponds to clause 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we agree with Ofcom's decision in full. We will adhere to the directive as soon as the date and wording are finalised."
