The BBC committed a "significant breach" of industry standards by omitting to mention that the presenter of a documentary about the Gaza situation was the offspring of a Hamas representative, as determined by regulatory body Ofcom.
An investigation by the media regulator into Gaza: How to Survive a Warzone has concluded that the documentary was "materially misleading".
The chief executive of the broadcaster had already issued an apology, saying there had been "a serious error in relation to accuracy".
The authority has instructed the corporation to air a prime-time declaration about its findings.
"Given this constitutes a major infringement of our code, we are instructing the BBC to broadcast a message of our determinations against it on BBC2 at 21:00, with a schedule to be determined," the statement read.
'Possibility to Damage Confidence'
The authority's report said: "Our investigation found that the documentary's failure to disclose that the voice's parent occupied a position in the Hamas-controlled authority was materially misleading.
"This implied that the public did not have critical information which may have been extremely pertinent to their assessment of the presenter and the information he presented.
"Confidence is at the core of the bond between a television network and its viewers, notably for a state-funded media outlet such as the BBC.
"This error had the potential to damage the very considerable degrees of trust that the public would have invested in a documentary produced by the BBC about the Israel-Gaza war."
The film was removed from the BBC's streaming service in the month of February after the narrator's familial connections emerged, and in the month of July an broadcaster's internal assessment determined it infringed the corporation's journalistic standards on factual correctness.
A BBC spokesperson commented: "The Ofcom ruling is in accordance with the results of Peter Johnston's review, that there was a serious error in the film in relation to the BBC's Editorial Guidelines on factual correctness, which reflects Rule 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we comply with Ofcom's decision in complete. We will comply with the directive as soon as the schedule and wording are determined."
