The BBC committed a "serious breach" of media regulations by not revealing that the presenter of a documentary about Gaza was the offspring of a Hamas representative, according to British broadcasting authority Ofcom.
An probe by the media regulator into the documentary titled Gaza: How to Survive a Warzone has determined that the documentary was "materially misleading".
The BBC's director general had already issued an apology, saying there had been "a serious error in relation to truthfulness".
Ofcom has directed the corporation to transmit a peak-time declaration about its decisions.
"Since this amounts to a significant violation of our rules, we are directing the broadcaster to air a message of our findings against it on BBC Two at 9pm, with a schedule to be determined," the regulator stated.
'Risk to Undermine Confidence'
The watchdog's statement declared: "The inquiry we conducted found that the programme's lack of disclosure that the presenter's parent served in a role in the Hamas-administered government was materially misleading.
"It meant that the audience did not have vital facts which may have been extremely pertinent to their assessment of the presenter and the content he shared.
"Confidence is at the center of the relationship between a broadcaster and its audience, especially for a public service broadcaster such as the public broadcaster.
"This error had the potential to undermine the very considerable levels of credibility that the public would have invested in a factual film from the broadcaster about the conflict in Gaza."
The documentary was withdrawn from the BBC's streaming service in last February after the narrator's familial connections emerged, and in July an internal BBC review concluded it infringed the organization's content policies on accuracy.
A representative for the broadcaster said: "The Ofcom ruling is in accordance with the findings of the corporation's inquiry, that there was a serious error in the film in relation to the broadcaster's journalistic policies on factual correctness, which aligns with regulation 2.2 of the regulator's media standards.
"We have apologised for this and we accept Ofcom's decision in full. We will comply with the sanction as soon as the schedule and language are determined."