The BBC committed a "significant breach" of media regulations by not revealing that the narrator of a film about Gaza was the son of a Hamas representative, according to UK media regulator Ofcom.
An investigation by the broadcasting watchdog into the programme Gaza: How to Survive a Warzone has concluded that the documentary was "materially misleading".
The head of the BBC had already issued an apology, saying there had been "a serious error in relation to accuracy".
The authority has instructed the corporation to transmit a peak-time announcement about its decisions.
"As this represents a major infringement of our code, we are instructing the BBC to broadcast a announcement of our determinations against it on the BBC's second channel at 21:00, with a timing to be finalised," it said.
'Risk to Undermine Credibility'
The authority's report said: "Our investigation concluded that the programme's failure to disclose that the voice's parent held a position in the Hamas-administered government was substantially inaccurate.
"This implied that the public did not have essential details which may have been extremely pertinent to their judgment of the presenter and the information he presented.
"Credibility is at the core of the connection between a television network and its audience, notably for a national broadcasting corporation such as the British Broadcasting Corporation.
"This error had the risk to damage the very considerable amounts of confidence that the public would have placed in a factual film from the broadcaster about the Gaza conflict."
The programme was removed from the BBC's streaming service in the month of February after the presenter's family links were revealed, and in the month of July an broadcaster's internal assessment found it breached the organization's content policies on factual correctness.
A BBC spokesperson commented: "The regulator's decision is in agreement with the conclusions of the corporation's inquiry, that there was a major oversight in the documentary in relation to the broadcaster's journalistic policies on factual correctness, which aligns with regulation 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we comply with Ofcom's decision in its entirety. We will comply with the sanction as soon as the date and wording are finalised."
