The public service broadcaster committed a "major breach" of broadcasting rules by failing to disclose that the voice of a programme about the Gaza situation was the son of a Hamas representative, according to regulatory body Ofcom.
An investigation by the broadcasting watchdog into the documentary titled Gaza: How to Survive a Warzone has concluded that the film was "materially misleading".
The chief executive of the broadcaster had previously apologised, stating there had been "a significant failing in relation to factual correctness".
The authority has directed the broadcaster to broadcast a peak-time declaration about its conclusions.
"As this represents a major infringement of our rules, we are instructing the corporation to broadcast a message of our conclusions against it on BBC2 at 21:00, with a date to be determined," it said.
'Potential to Damage Credibility'
The watchdog's announcement said: "Our probe determined that the documentary's omission to reveal that the voice's parent held a role in the Hamas-administered government was materially misleading.
"This implied that the audience did not have critical information which may have been very significant to their judgment of the presenter and the content he presented.
"Trust is at the heart of the connection between a television network and its audience, especially for a state-funded media outlet such as the public broadcaster.
"This failing had the risk to damage the exceptionally strong levels of confidence that audiences would have invested in a documentary produced by the BBC about the conflict in Gaza."
The film was withdrawn from the online platform in last February after the presenter's family links came to light, and in the month of July an internal BBC review concluded it breached the broadcaster's editorial guidelines on truthfulness.
A representative for the broadcaster said: "The regulator's decision is in line with the findings of Peter Johnston's review, that there was a major oversight in the film in relation to the corporation's content standards on truthfulness, which corresponds to Rule 2.2 of the regulator's media standards.
"We have apologised for this and we agree with the authority's determination in full. We will adhere to the penalty as soon as the timing and wording are finalised."
