The BBC committed a "serious breach" of broadcasting rules by failing to disclose that the presenter of a programme about the Gaza conflict was the offspring of a Hamas official, as determined by regulatory body Ofcom.
An inquiry by the broadcasting watchdog into Gaza: How to Survive a Warzone has determined that the documentary was "substantially inaccurate".
The chief executive of the broadcaster had earlier expressed regret, stating there had been "a major oversight in relation to factual correctness".
The authority has instructed the corporation to transmit a peak-time declaration about its conclusions.
"Since this amounts to a major infringement of our code, we are directing the broadcaster to air a announcement of our conclusions against it on BBC2 at nine o'clock in the evening, with a schedule to be finalised," the statement read.
'Potential to Undermine Credibility'
The watchdog's announcement said: "The inquiry we conducted determined that the film's lack of disclosure that the presenter's father served in a post in the Hamas-controlled government was substantially inaccurate.
"It meant that the viewers did not have vital facts which may have been highly relevant to their assessment of the narrator and the information he presented.
"Confidence is at the center of the relationship between a broadcaster and its public, notably for a national broadcasting corporation such as the public broadcaster.
"This error had the possibility to erode the very considerable levels of credibility that audiences would have put in a factual film from the broadcaster about the Gaza conflict."
The documentary was removed from iPlayer in last February after the boy's personal associations emerged, and in July an internal BBC review concluded it violated the broadcaster's journalistic standards on accuracy.
A representative for the broadcaster commented: "The regulator's decision is in agreement with the findings of the corporation's inquiry, that there was a significant failing in the documentary in relation to the corporation's content standards on accuracy, which corresponds to clause 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we agree with the authority's determination in complete. We will follow the penalty as soon as the schedule and wording are determined."
