The BBC engaged in a "serious breach" of media regulations by omitting to mention that the narrator of a film about the Gaza conflict was the offspring of a Hamas official, according to British broadcasting authority Ofcom.
An inquiry by the broadcasting watchdog into the programme Gaza: How to Survive a Warzone has found that the film was "substantially inaccurate".
The BBC's director general had previously apologised, saying there had been "a serious error in relation to factual correctness".
Ofcom has instructed the broadcaster to transmit a evening announcement about its findings.
"As this represents a major infringement of our regulations, we are ordering the BBC to air a message of our conclusions against it on the BBC's second channel at nine o'clock in the evening, with a date to be determined," it said.
'Risk to Damage Trust'
The authority's statement declared: "Our probe found that the film's omission to reveal that the narrator's father occupied a position in the Hamas-controlled government was materially misleading.
"Consequently that the public did not have essential details which may have been highly relevant to their evaluation of the presenter and the information he shared.
"Credibility is at the heart of the connection between a television network and its audience, notably for a state-funded media outlet such as the public broadcaster.
"This failing had the potential to damage the very considerable degrees of credibility that viewers would have put in a documentary produced by the BBC about the conflict in Gaza."
The film was removed from iPlayer in February after the presenter's familial connections were revealed, and in the month of July an broadcaster's internal assessment found it violated the broadcaster's content policies on factual correctness.
A BBC spokesperson stated: "The authority's determination is in agreement with the results of Peter Johnston's review, that there was a significant failing in the film in relation to the corporation's content standards on accuracy, which corresponds to regulation 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we comply with Ofcom's decision in full. We will comply with the penalty as soon as the timing and wording are determined."
