The BBC engaged in a "serious breach" of media regulations by not revealing that the voice of a programme about the Gaza situation was the son of a Hamas administrator, according to British broadcasting authority Ofcom.
An investigation by Ofcom into the programme Gaza: How to Survive a Warzone has found that the programme was "materially misleading".
The head of the BBC had previously apologised, stating there had been "a major oversight in relation to factual correctness".
The authority has directed the BBC to transmit a peak-time declaration about its findings.
"Given this constitutes a major infringement of our regulations, we are instructing the corporation to air a statement of our conclusions against it on BBC Two at nine o'clock in the evening, with a timing to be finalised," the regulator stated.
'Possibility to Erode Confidence'
The regulator's statement stated: "The inquiry we conducted concluded that the programme's omission to reveal that the presenter's parent held a post in the Hamas-run administration was materially misleading.
"Consequently that the viewers did not have essential details which may have been highly relevant to their evaluation of the voice and the information he shared.
"Trust is at the core of the connection between a media organization and its public, especially for a national broadcasting corporation such as the public broadcaster.
"This oversight had the potential to erode the exceptionally strong amounts of confidence that viewers would have put in a documentary produced by the BBC about the Gaza conflict."
The film was removed from the BBC's streaming service in February after the presenter's familial connections emerged, and in July an internal BBC review concluded it violated the corporation's content policies on accuracy.
A representative for the broadcaster said: "The authority's determination is in agreement with the findings of Peter Johnston's review, that there was a serious error in the documentary in relation to the corporation's content standards on accuracy, which corresponds to Rule 2.2 of the regulator's media standards.
"We issued an apology for this and we agree with Ofcom's decision in its entirety. We will follow the directive as soon as the date and language are finalised."
