The BBC committed a "significant breach" of industry standards by failing to disclose that the voice of a film about Gaza was the child of a Hamas official, as determined by regulatory body Ofcom.
An investigation by the media regulator into the documentary titled Gaza: How to Survive a Warzone has found that the programme was "materially misleading".
The head of the BBC had earlier expressed regret, saying there had been "a significant failing in relation to truthfulness".
The regulator has ordered the broadcaster to air a peak-time declaration about its decisions.
"Since this amounts to a major infringement of our rules, we are ordering the corporation to broadcast a announcement of our conclusions against it on BBC Two at 9pm, with a timing to be finalised," the statement read.
'Possibility to Undermine Credibility'
The authority's announcement declared: "Our investigation found that the film's omission to reveal that the presenter's father held a role in the Hamas-administered authority was substantially inaccurate.
"It meant that the audience did not have critical information which may have been highly relevant to their judgment of the narrator and the information he provided.
"Confidence is at the center of the relationship between a television network and its viewers, particularly for a national broadcasting corporation such as the BBC.
"This oversight had the potential to undermine the significantly high amounts of trust that audiences would have put in a documentary produced by the BBC about the Israel-Gaza war."
The film was removed from the online platform in February after the boy's family links were revealed, and in July an internal BBC review found it violated the organization's content policies on truthfulness.
A corporation official commented: "The Ofcom ruling is in accordance with the conclusions of the corporation's inquiry, that there was a serious error in the film in relation to the BBC's Editorial Guidelines on factual correctness, which aligns with regulation 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we comply with the regulator's ruling in complete. We will comply with the penalty as soon as the schedule and language are confirmed."
