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 official, as determined by UK media regulator Ofcom.
An inquiry by the broadcasting watchdog into Gaza: How to Survive a Warzone has concluded that the programme was "substantially inaccurate".
The BBC's director general had already issued an apology, stating there had been "a major oversight in relation to truthfulness".
Ofcom has directed the broadcaster to transmit a prime-time declaration about its decisions.
"Since this amounts to a significant violation of our rules, we are ordering the broadcaster to transmit a announcement of our findings against it on BBC2 at 21:00, with a schedule to be finalised," it said.
'Possibility to Undermine Credibility'
The regulator's statement said: "Our investigation determined that the film's lack of disclosure that the voice's parent served in a role in the Hamas-administered government was significantly deceptive.
"It meant that the public did not have vital facts which may have been extremely pertinent to their evaluation of the presenter and the content he shared.
"Credibility is at the core of the relationship between a media organization and its audience, notably for a state-funded media outlet such as the BBC.
"This failing had the risk to undermine the significantly high amounts of credibility that audiences would have placed in a BBC factual programme about the Israel-Gaza war."
The documentary was withdrawn from iPlayer in the month of February after the boy's familial connections came to light, and in this past July an internal BBC review found it breached the organization's journalistic standards on truthfulness.
A BBC spokesperson said: "The Ofcom ruling is in agreement with the results of Peter Johnston's review, that there was a serious error in the documentary in relation to the broadcaster's journalistic policies on truthfulness, which aligns with regulation 2.2 of Ofcom's Broadcasting Code.
"We expressed regret for this and we accept Ofcom's decision in its entirety. We will follow the sanction as soon as the schedule and wording are confirmed."
