The BBC committed a "serious breach" of industry standards by not revealing that the presenter of a programme about the Gaza conflict was the son of a Hamas official, according to British broadcasting authority Ofcom.
An investigation by the media regulator into Gaza: How to Survive a Warzone has found that the film was "substantially inaccurate".
The BBC's director general had previously apologised, stating there had been "a major oversight in relation to factual correctness".
The regulator has ordered the BBC to air a evening declaration about its conclusions.
"As this represents a major infringement of our regulations, we are directing the corporation to broadcast a statement of our conclusions against it on BBC Two at 21:00, with a date to be determined," it said.
'Risk to Damage Trust'
The watchdog's announcement stated: "Our investigation found that the documentary's lack of disclosure that the narrator's parent occupied a position in the Hamas-controlled authority was materially misleading.
"It meant that the public did not have essential details which may have been highly relevant to their evaluation of the voice and the details he shared.
"Credibility is at the heart of the relationship between a television network and its audience, notably for a national broadcasting corporation such as the public broadcaster.
"This failing had the potential to undermine the significantly high amounts of credibility that the public would have placed in a factual film from the broadcaster about the conflict in Gaza."
The film was removed from iPlayer in last February after the boy's personal associations came to light, and in this past July an broadcaster's internal assessment concluded it infringed the corporation's content policies on truthfulness.
A BBC spokesperson said: "The regulator's decision is in line with the results of the corporation's inquiry, that there was a major oversight in the documentary in relation to the broadcaster's journalistic policies on accuracy, which reflects clause 2.2 of the authority's broadcasting regulations.
"We have apologised for this and we accept Ofcom's decision in its entirety. We will follow the directive as soon as the schedule and language are confirmed."
