The British broadcaster committed a "serious breach" of industry standards by failing to disclose that the voice of a documentary about the Gaza conflict was the child of a Hamas official, as determined by regulatory body Ofcom.
An investigation by Ofcom into the programme Gaza: How to Survive a Warzone has found that the film was "materially misleading".
The BBC's director general had previously apologised, noting there had been "a serious error in relation to accuracy".
The regulator has directed the BBC to transmit a evening announcement about its findings.
"As this represents a significant violation of our rules, we are instructing the corporation to transmit a message of our findings against it on the BBC's second channel at nine o'clock in the evening, with a timing to be determined," it said.
'Possibility to Damage Credibility'
The regulator's statement stated: "The inquiry we conducted determined that the film's omission to reveal that the voice's male guardian served in a position in the Hamas-administered government was substantially inaccurate.
"This implied that the audience did not have vital facts which may have been highly relevant to their assessment of the voice and the information he provided.
"Trust is at the core of the connection between a broadcaster and its public, notably for a public service broadcaster such as the public broadcaster.
"This error had the possibility to damage the exceptionally strong levels of confidence that viewers would have put in a documentary produced by the BBC about the conflict in Gaza."
The film was withdrawn from iPlayer in last February after the boy's personal associations came to light, and in this past July an corporation's own inquiry concluded it violated the corporation's content policies on truthfulness.
A corporation official stated: "The regulator's decision is in line with the conclusions of the internal assessment, that there was a significant failing in the film in relation to the BBC's Editorial Guidelines on factual correctness, which aligns with regulation 2.2 of the regulator's media standards.
"We expressed regret for this and we agree with the regulator's ruling in complete. We will follow the sanction as soon as the schedule and wording are determined."
