The BBC committed a "major breach" of broadcasting rules by failing to disclose that the narrator of a documentary about Gaza was the offspring of a Hamas official, as ruled by regulatory body Ofcom.
An investigation by the broadcasting watchdog into Gaza: How to Survive a Warzone has determined that the programme was "significantly deceptive".
The head of the BBC had already issued an apology, saying there had been "a major oversight in relation to truthfulness".
Ofcom has ordered the corporation to broadcast a evening announcement about its findings.
"Given this constitutes a significant violation of our code, we are instructing the corporation to broadcast a message of our findings against it on BBC2 at 9pm, with a date to be confirmed," the statement read.
'Risk to Erode Trust'
The authority's announcement said: "Our probe concluded that the documentary's omission to reveal that the presenter's parent held a position in the Hamas-controlled authority was materially misleading.
"It meant that the viewers did not have critical information which may have been highly relevant to their assessment of the narrator and the details he presented.
"Credibility is at the core of the relationship between a television network and its public, especially for a public service broadcaster such as the BBC.
"This failing had the risk to erode the exceptionally strong levels of confidence that the public would have invested in a documentary produced by the BBC about the Gaza conflict."
The programme was removed from the BBC's streaming service in last February after the narrator's family links came to light, and in the month of July an corporation's own inquiry determined it breached the organization's content policies on accuracy.
A corporation official commented: "The authority's determination is in line with the conclusions of the internal assessment, that there was a significant failing in the film in relation to the BBC's Editorial Guidelines on truthfulness, which aligns with regulation 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we accept the regulator's ruling in its entirety. We will comply with the directive as soon as the timing and language are finalised."
