The BBC committed a "serious breach" of media regulations by failing to disclose that the presenter of a programme about the Gaza situation was the child of a Hamas administrator, as determined by UK media regulator Ofcom.
An investigation by Ofcom into Gaza: How to Survive a Warzone has found that the film was "significantly deceptive".
The chief executive of the broadcaster had previously apologised, noting there had been "a serious error in relation to factual correctness".
The regulator has directed the BBC to air a evening announcement about its findings.
"As this represents a serious breach of our code, we are instructing the broadcaster to broadcast a statement of our conclusions against it on BBC2 at 9pm, with a schedule to be confirmed," the statement read.
'Possibility to Undermine Credibility'
The regulator's report stated: "Our probe concluded that the documentary's lack of disclosure that the voice's father served in a role in the Hamas-controlled government was materially misleading.
"Consequently that the viewers did not have vital facts which may have been very significant to their judgment of the voice and the information he presented.
"Confidence is at the core of the relationship between a media organization and its viewers, especially for a national broadcasting corporation such as the BBC.
"This oversight had the risk to undermine the very considerable levels of trust that viewers would have placed in a BBC factual programme about the Israel-Gaza war."
The programme was withdrawn from the online platform in last February after the presenter's family links came to light, and in July an broadcaster's internal assessment determined it violated the organization's journalistic standards on factual correctness.
A corporation official stated: "The regulator's decision is in accordance with the results of Peter Johnston's review, that there was a serious error in the documentary in relation to the BBC's Editorial Guidelines on accuracy, which corresponds to clause 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we accept the regulator's ruling in its entirety. We will comply with the penalty as soon as the date and wording are confirmed."
