The British broadcaster engaged in a "significant breach" of industry standards by failing to disclose that the narrator of a programme about Gaza was the son of a Hamas administrator, according to UK media regulator Ofcom.
An investigation by Ofcom into Gaza: How to Survive a Warzone has concluded that the film was "substantially inaccurate".
The chief executive of the broadcaster had already issued an apology, saying there had been "a major oversight in relation to truthfulness".
The regulator has ordered the BBC to transmit a evening declaration about its decisions.
"As this represents a serious breach of our rules, we are ordering the corporation to air a statement of our conclusions against it on the BBC's second channel at 21:00, with a timing to be finalised," the regulator stated.
'Risk to Undermine Confidence'
The watchdog's statement stated: "Our probe determined that the documentary's lack of disclosure that the voice's father served in a role in the Hamas-controlled administration was significantly deceptive.
"Consequently that the viewers did not have critical information which may have been highly relevant to their evaluation of the presenter and the content he shared.
"Trust is at the center of the relationship between a broadcaster and its viewers, especially for a national broadcasting corporation such as the British Broadcasting Corporation.
"This oversight had the potential to damage the very considerable degrees of trust that the public would have placed in a BBC factual programme about the Gaza conflict."
The documentary was withdrawn from the BBC's streaming service in February after the boy's familial connections were revealed, and in July an corporation's own inquiry determined it infringed the corporation's editorial guidelines on factual correctness.
A BBC spokesperson stated: "The authority's determination is in line with the conclusions of Peter Johnston's review, that there was a major oversight in the programme in relation to the corporation's content standards on accuracy, which aligns with clause 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we agree with the authority's determination in full. We will comply with the sanction as soon as the date and wording are determined."
