The BBC was found to have committed a "major breach" of media regulations by not revealing that the voice of a film about Gaza was the offspring of a Hamas representative, according to British broadcasting authority Ofcom.
An inquiry by the broadcasting watchdog into Gaza: How to Survive a Warzone has found that the documentary was "significantly deceptive".
The chief executive of the broadcaster had earlier expressed regret, noting there had been "a serious error in relation to factual correctness".
The regulator has instructed the corporation to air a peak-time announcement about its decisions.
"As this represents a serious breach of our regulations, we are instructing the broadcaster to air a announcement of our determinations against it on the BBC's second channel at 9pm, with a timing to be determined," the statement read.
'Potential to Erode Confidence'
The authority's announcement said: "Our investigation found that the documentary's omission to reveal that the narrator's father occupied a post in the Hamas-run government was substantially inaccurate.
"This implied that the public did not have vital facts which may have been very significant to their evaluation of the presenter and the details he shared.
"Confidence is at the heart of the bond between a broadcaster and its viewers, particularly for a national broadcasting corporation such as the British Broadcasting Corporation.
"This failing had the possibility to erode the significantly high amounts of trust that audiences would have placed in a factual film from the broadcaster about the Israel-Gaza war."
The film was pulled from iPlayer in February after the presenter's familial connections emerged, and in July an corporation's own inquiry concluded it infringed the organization's content policies on factual correctness.
A BBC spokesperson said: "The Ofcom ruling is in accordance with the conclusions of Peter Johnston's review, that there was a major oversight in the documentary in relation to the corporation's content standards on truthfulness, which corresponds to clause 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we comply with the authority's determination in complete. We will comply with the directive as soon as the timing and wording are finalised."
