The British broadcaster engaged in a "serious breach" of broadcasting rules by omitting to mention that the presenter of a programme about the Gaza situation was the offspring of a Hamas official, as determined by British broadcasting authority Ofcom.
An investigation by the broadcasting watchdog into Gaza: How to Survive a Warzone has concluded that the documentary was "materially misleading".
The BBC's director general had already issued an apology, saying there had been "a serious error in relation to truthfulness".
The authority has directed the broadcaster to transmit a evening declaration about its findings.
"Given this constitutes a significant violation of our rules, we are instructing the BBC to transmit a message of our findings against it on BBC2 at nine o'clock in the evening, with a timing to be determined," the regulator stated.
'Possibility to Erode Trust'
The watchdog's report said: "Our probe determined that the film's failure to disclose that the voice's parent held a position in the Hamas-controlled administration was materially misleading.
"This implied that the viewers did not have essential details which may have been very significant to their judgment of the voice and the information he presented.
"Trust is at the core of the bond between a media organization and its viewers, particularly for a public service broadcaster such as the British Broadcasting Corporation.
"This failing had the potential to undermine the very considerable levels of trust that audiences would have placed in a documentary produced by the BBC about the Gaza conflict."
The documentary was withdrawn from the BBC's streaming service in February after the presenter's familial connections emerged, and in this past July an broadcaster's internal assessment concluded it infringed the organization's editorial guidelines on accuracy.
A BBC spokesperson stated: "The Ofcom ruling is in agreement with the conclusions of the corporation's inquiry, that there was a significant failing in the film in relation to the broadcaster's journalistic policies on accuracy, which aligns with clause 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we accept Ofcom's decision in full. We will follow the directive as soon as the timing and language are determined."
