The BBC engaged in a "significant breach" of media regulations by omitting to mention that the voice of a documentary about the Gaza situation was the offspring of a Hamas official, as determined by British broadcasting authority Ofcom.
An inquiry by the media regulator into the documentary titled Gaza: How to Survive a Warzone has concluded that the programme was "significantly deceptive".
The BBC's director general had earlier expressed regret, saying there had been "a significant failing in relation to accuracy".
Ofcom has instructed the broadcaster to broadcast a prime-time declaration about its findings.
"Given this constitutes a serious breach of our regulations, we are ordering the broadcaster to air a message of our findings against it on BBC2 at 9pm, with a date to be confirmed," it said.
'Possibility to Erode Credibility'
The watchdog's report stated: "Our probe found that the film's failure to disclose that the narrator's father served in a position in the Hamas-run government was substantially inaccurate.
"It meant that the audience did not have critical information which may have been very significant to their judgment of the narrator and the details he provided.
"Credibility is at the center of the bond between a broadcaster and its public, particularly for a state-funded media outlet such as the public broadcaster.
"This failing had the potential to erode the very considerable levels of trust that audiences would have put in a documentary produced by the BBC about the conflict in Gaza."
The documentary was withdrawn from the online platform in the month of February after the presenter's familial connections came to light, and in July an broadcaster's internal assessment determined it infringed the organization's content policies on factual correctness.
A corporation official said: "The authority's determination is in agreement with the findings of Peter Johnston's review, that there was a significant failing in the film in relation to the BBC's Editorial Guidelines on truthfulness, which corresponds to regulation 2.2 of the regulator's media standards.
"We have apologised for this and we accept the authority's determination in its entirety. We will comply with the directive as soon as the schedule and wording are finalised."
