The BBC committed a "serious breach" of media regulations by not revealing that the narrator of a programme about Gaza was the offspring of a Hamas representative, according to British broadcasting authority Ofcom.
An investigation by the broadcasting watchdog into Gaza: How to Survive a Warzone has found that the film was "significantly deceptive".
The head of the BBC had earlier expressed regret, stating there had been "a major oversight in relation to factual correctness".
Ofcom has directed the BBC to broadcast a prime-time announcement about its conclusions.
"Since this amounts to a serious breach of our code, we are ordering the corporation to transmit a message of our determinations against it on BBC Two at 9pm, with a timing to be confirmed," the statement read.
'Possibility to Undermine Confidence'
The authority's statement stated: "Our probe found that the programme's omission to reveal that the presenter's father held a position in the Hamas-run government was significantly deceptive.
"Consequently that the public did not have critical information which may have been very significant to their judgment of the presenter and the content he provided.
"Credibility is at the core of the connection between a television network and its audience, especially for a public service broadcaster such as the British Broadcasting Corporation.
"This error had the risk to damage the significantly high amounts of confidence that viewers would have placed in a documentary produced by the BBC about the conflict in Gaza."
The film was pulled from the BBC's streaming service in the month of February after the presenter's family links came to light, and in the month of July an internal BBC review found it violated the corporation's content policies on accuracy.
A representative for the broadcaster stated: "The authority's determination is in agreement with the findings of Peter Johnston's review, that there was a serious error in the film in relation to the corporation's content standards on accuracy, which aligns with clause 2.2 of the regulator's media standards.
"We have apologised for this and we comply with the regulator's ruling in full. We will adhere to the sanction as soon as the schedule and language are finalised."
