The BBC was found to have committed a "major breach" of broadcasting rules by not revealing that the presenter of a programme about Gaza was the child of a Hamas representative, as determined by regulatory body Ofcom.
An investigation by the broadcasting watchdog into Gaza: How to Survive a Warzone has determined that the documentary was "materially misleading".
The chief executive of the broadcaster had earlier expressed regret, stating there had been "a major oversight in relation to accuracy".
The regulator has instructed the broadcaster to air a prime-time announcement about its findings.
"Given this constitutes a significant violation of our regulations, we are directing the BBC to broadcast a message of our determinations against it on the BBC's second channel at 21:00, with a date to be determined," it said.
'Risk to Erode Trust'
The regulator's announcement declared: "Our investigation concluded that the programme's lack of disclosure that the voice's parent served in a position in the Hamas-controlled government was materially misleading.
"Consequently that the viewers did not have vital facts which may have been highly relevant to their evaluation of the voice and the content he provided.
"Confidence is at the center of the bond between a broadcaster and its public, especially for a public service broadcaster such as the public broadcaster.
"This error had the possibility to erode the significantly high degrees of trust that the public would have invested in a factual film from the broadcaster about the Israel-Gaza war."
The documentary was removed from the BBC's streaming service in last February after the presenter's family links came to light, and in this past July an internal BBC review concluded it violated the corporation's journalistic standards on accuracy.
A BBC spokesperson commented: "The authority's determination is in line with the findings 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 corresponds to Rule 2.2 of the regulator's media standards.
"We expressed regret for this and we agree with Ofcom's decision in its entirety. We will comply with the directive as soon as the schedule and wording are determined."
