The BBC committed a "major breach" of broadcasting rules by not revealing that the narrator of a documentary about the Gaza conflict was the child of a Hamas representative, as determined by British broadcasting authority Ofcom.
An inquiry by the media regulator into the documentary titled Gaza: How to Survive a Warzone has found that the programme was "materially misleading".
The chief executive of the broadcaster had earlier expressed regret, stating there had been "a significant failing in relation to accuracy".
The authority has ordered the broadcaster to broadcast a evening announcement about its decisions.
"Since this amounts to a significant violation of our rules, we are ordering the broadcaster to broadcast a message of our findings against it on the BBC's second channel at 21:00, with a timing to be determined," the statement read.
'Risk to Damage Confidence'
The watchdog's statement declared: "The inquiry we conducted found that the programme's lack of disclosure that the voice's father held a post in the Hamas-run government was significantly deceptive.
"It meant that the public did not have essential details which may have been extremely pertinent to their assessment of the voice and the information he shared.
"Trust is at the heart of the relationship between a media organization and its viewers, particularly for a national broadcasting corporation such as the British Broadcasting Corporation.
"This failing had the risk to damage the significantly high amounts of trust that viewers would have placed in a documentary produced by the BBC about the conflict in Gaza."
The film was withdrawn from the BBC's streaming service in February after the presenter's familial connections emerged, and in July an internal BBC review found it infringed the broadcaster's editorial guidelines on factual correctness.
A BBC spokesperson stated: "The authority's determination is in accordance with the conclusions 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 clause 2.2 of the regulator's media standards.
"We issued an apology for this and we agree with the authority's determination in complete. We will follow the penalty as soon as the schedule and language are confirmed."