The BBC engaged in a "significant breach" of broadcasting rules by not revealing that the voice of a film about the Gaza situation was the offspring of a Hamas administrator, as ruled by regulatory body Ofcom.
An inquiry by the broadcasting watchdog into Gaza: How to Survive a Warzone has determined that the film was "substantially inaccurate".
The chief executive of the broadcaster had earlier expressed regret, saying there had been "a serious error in relation to truthfulness".
Ofcom has instructed the BBC to air a peak-time statement about its conclusions.
"As this represents a significant violation of our rules, we are directing the corporation to air 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 confirmed," the regulator stated.
'Possibility to Erode Confidence'
The authority's announcement stated: "Our investigation concluded that the programme's omission to reveal that the voice's father held a role in the Hamas-controlled government was significantly deceptive.
"It meant that the audience did not have critical information which may have been highly relevant to their assessment of the voice and the details he shared.
"Confidence is at the core of the bond between a broadcaster and its public, notably for a public service broadcaster such as the BBC.
"This error had the possibility to damage the significantly high levels of confidence that audiences would have placed in a factual film from the broadcaster about the Israel-Gaza war."
The programme was pulled from iPlayer in last February after the presenter's familial connections were revealed, and in the month of July an internal BBC review concluded it violated the organization's journalistic standards on factual correctness.
A corporation official said: "The regulator's decision is in accordance with the findings of the corporation's inquiry, that there was a serious error in the documentary in relation to the corporation's content standards on truthfulness, which corresponds to clause 2.2 of the regulator's media standards.
"We expressed regret for this and we accept the authority's determination in its entirety. We will comply with the sanction as soon as the date and language are finalised."
