The BBC committed a "significant breach" of broadcasting rules by omitting to mention that the presenter of a documentary about the Gaza conflict was the child of a Hamas official, as ruled by British broadcasting authority Ofcom.
An inquiry by the broadcasting watchdog into Gaza: How to Survive a Warzone has concluded that the documentary was "substantially inaccurate".
The chief executive of the broadcaster had earlier expressed regret, stating there had been "a significant failing in relation to truthfulness".
The authority has ordered the corporation to broadcast a prime-time declaration about its decisions.
"Given this constitutes a significant violation of our regulations, we are instructing the BBC to transmit a announcement of our findings against it on BBC2 at nine o'clock in the evening, with a schedule to be determined," the statement read.
'Potential to Undermine Confidence'
The authority's report declared: "The inquiry we conducted determined that the programme's failure to disclose that the voice's father served in a position in the Hamas-run government was materially misleading.
"This implied that the audience did not have essential details which may have been extremely pertinent to their assessment of the voice and the content he provided.
"Credibility is at the center of the bond between a television network and its viewers, especially for a state-funded media outlet such as the public broadcaster.
"This error had the risk to undermine the significantly high amounts of confidence that viewers would have placed in a documentary produced by the BBC about the conflict in Gaza."
The documentary was withdrawn from the BBC's streaming service in last February after the narrator's personal associations came to light, and in July an corporation's own inquiry concluded it violated the organization's content policies on factual correctness.
A BBC spokesperson said: "The authority's determination is in agreement with the conclusions 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 reflects regulation 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we comply with the authority's determination in its entirety. We will follow the penalty as soon as the date and language are confirmed."
