The BBC committed a "serious breach" of industry standards by omitting to mention that the presenter of a programme about Gaza was the son of a Hamas official, according to UK media regulator Ofcom.
An investigation by the broadcasting watchdog into the programme Gaza: How to Survive a Warzone has concluded that the programme was "materially misleading".
The chief executive of the broadcaster had previously apologised, stating there had been "a significant failing in relation to truthfulness".
Ofcom has ordered the BBC to air a evening declaration about its findings.
"As this represents a serious breach of our regulations, we are ordering the BBC to transmit a message of our conclusions against it on BBC Two at nine o'clock in the evening, with a schedule to be confirmed," the regulator stated.
'Potential to Damage Credibility'
The watchdog's statement said: "Our probe determined that the documentary's failure to disclose that the presenter's parent held a role in the Hamas-controlled authority was substantially inaccurate.
"This implied that the audience did not have critical information which may have been very significant to their judgment of the narrator and the content he presented.
"Credibility is at the heart of the relationship between a television network and its audience, especially for a national broadcasting corporation such as the British Broadcasting Corporation.
"This failing had the risk to undermine the exceptionally strong levels of confidence that audiences would have invested in a factual film from the broadcaster about the Israel-Gaza war."
The documentary was withdrawn from the online platform in February after the boy's familial connections were revealed, and in this past July an broadcaster's internal assessment concluded it infringed the organization's journalistic standards on accuracy.
A representative for the broadcaster said: "The regulator's decision is in agreement with the results of the corporation's inquiry, that there was a serious error in the documentary in relation to the broadcaster's journalistic policies on accuracy, which reflects regulation 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we comply with Ofcom's decision in its entirety. We will follow the sanction as soon as the date and wording are confirmed."
