The BBC was found to have committed a "serious breach" of industry standards by failing to disclose that the voice of a programme about the Gaza situation was the offspring of a Hamas official, according to regulatory body Ofcom.
An investigation by Ofcom into the programme Gaza: How to Survive a Warzone has determined that the programme was "materially misleading".
The BBC's director general had previously apologised, stating there had been "a significant failing in relation to truthfulness".
The regulator has directed the broadcaster to air a prime-time statement about its findings.
"Given this constitutes a significant violation of our regulations, we are directing the corporation to air a statement of our determinations against it on BBC Two at 21:00, with a schedule to be finalised," it said.
'Potential to Undermine Credibility'
The watchdog's announcement said: "Our probe concluded that the film's omission to reveal that the voice's father held a post in the Hamas-run administration was significantly deceptive.
"Consequently that the audience did not have vital facts which may have been extremely pertinent to their assessment of the voice and the content he presented.
"Confidence is at the center of the relationship between a media organization and its audience, particularly for a state-funded media outlet such as the public broadcaster.
"This oversight had the potential to damage the very considerable amounts of trust that the public would have invested in a BBC factual programme about the conflict in Gaza."
The programme was removed from iPlayer in February after the presenter's familial connections were revealed, and in this past July an broadcaster's internal assessment concluded it violated the corporation's content policies on accuracy.
A corporation official stated: "The authority's determination is in agreement with the results of Peter Johnston's review, that there was a major oversight in the documentary in relation to the BBC's Editorial Guidelines on accuracy, which corresponds to Rule 2.2 of the regulator's media standards.
"We expressed regret for this and we comply with the authority's determination in its entirety. We will follow the directive as soon as the date and language are finalised."
