The British broadcaster committed a "significant breach" of media regulations by not revealing that the voice of a documentary about Gaza was the son of a Hamas official, as determined by British broadcasting authority Ofcom.
An investigation by Ofcom into the documentary titled Gaza: How to Survive a Warzone has determined that the documentary was "materially misleading".
The chief executive of the broadcaster had previously apologised, saying there had been "a major oversight in relation to accuracy".
The regulator has ordered the corporation to air a peak-time announcement about its findings.
"Given this constitutes a major infringement of our code, we are directing the corporation to broadcast a message of our conclusions against it on the BBC's second channel at nine o'clock in the evening, with a date to be determined," the regulator stated.
'Potential to Erode Confidence'
The authority's report declared: "The inquiry we conducted concluded that the film's lack of disclosure that the presenter's male guardian served in a role in the Hamas-controlled government was substantially inaccurate.
"Consequently that the audience did not have essential details which may have been highly relevant to their assessment of the narrator and the details he presented.
"Confidence is at the heart of the relationship between a broadcaster and its public, notably for a national broadcasting corporation such as the public broadcaster.
"This error had the risk to damage the very considerable amounts of confidence that viewers would have placed in a documentary produced by the BBC about the Israel-Gaza war."
The programme was pulled from the BBC's streaming service in February after the presenter's family links came to light, and in July an broadcaster's internal assessment concluded it infringed the corporation's journalistic standards on factual correctness.
A representative for the broadcaster stated: "The Ofcom ruling is in agreement with the conclusions of Peter Johnston's review, that there was a significant failing in the film in relation to the BBC's Editorial Guidelines on truthfulness, which reflects clause 2.2 of the authority's broadcasting regulations.
"We have apologised for this and we comply with the authority's determination in full. We will adhere to the sanction as soon as the timing and language are determined."
