The BBC was found to have committed a "major breach" of broadcasting rules by not revealing that the narrator of a programme about the Gaza situation was the offspring of a Hamas official, according to British broadcasting authority Ofcom.
An probe by Ofcom into Gaza: How to Survive a Warzone has found that the programme was "substantially inaccurate".
The BBC's director general had earlier expressed regret, stating there had been "a serious error in relation to accuracy".
The authority has instructed the broadcaster to air a evening announcement about its decisions.
"Since this amounts to a serious breach of our regulations, we are instructing the broadcaster to air a message of our findings against it on the BBC's second channel at 21:00, with a timing to be finalised," it said.
'Risk to Damage Trust'
The authority's statement declared: "Our investigation determined that the documentary's lack of disclosure that the voice's male guardian served in a post in the Hamas-run authority was significantly deceptive.
"Consequently that the audience did not have essential details which may have been highly relevant to their evaluation of the narrator and the content he provided.
"Credibility is at the heart of the bond between a media organization and its public, notably for a national broadcasting corporation such as the BBC.
"This error had the risk to erode the significantly high levels of trust that viewers would have put in a documentary produced by the BBC about the Gaza conflict."
The programme was pulled from the online platform in February after the presenter's familial connections emerged, and in the month of July an corporation's own inquiry concluded it infringed the corporation's editorial guidelines on factual correctness.
A representative for the broadcaster commented: "The Ofcom ruling is in agreement 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 corresponds to regulation 2.2 of Ofcom's Broadcasting Code.
"We expressed regret for this and we comply with the authority's determination in full. We will adhere to the penalty as soon as the date and wording are determined."
