The British broadcaster was found to have committed a "significant breach" of media regulations by not revealing that the voice of a programme about the Gaza conflict was the son of a Hamas representative, according to regulatory body Ofcom.
An investigation by Ofcom into the documentary titled Gaza: How to Survive a Warzone has determined that the film was "substantially inaccurate".
The chief executive of the broadcaster had previously apologised, stating there had been "a serious error in relation to truthfulness".
Ofcom has instructed the BBC to transmit a peak-time statement about its conclusions.
"Given this constitutes a significant violation of our rules, we are directing the corporation to transmit a statement of our determinations against it on BBC Two at 21:00, with a date to be finalised," the statement read.
'Risk to Damage Confidence'
The watchdog's statement said: "Our investigation determined that the film's lack of disclosure that the voice's male guardian held a position in the Hamas-administered government was substantially inaccurate.
"This implied that the viewers did not have essential details which may have been extremely pertinent to their evaluation of the presenter and the content he provided.
"Trust is at the heart of the relationship between a broadcaster and its audience, notably for a state-funded media outlet such as the British Broadcasting Corporation.
"This error had the risk to erode the very considerable levels of confidence that viewers would have invested in a documentary produced by the BBC about the conflict in Gaza."
The documentary was withdrawn from iPlayer in February after the presenter's personal associations came to light, and in this past July an internal BBC review found it violated the corporation's editorial guidelines on truthfulness.
A BBC spokesperson commented: "The Ofcom ruling is in accordance with the conclusions of Peter Johnston's review, that there was a serious error in the documentary in relation to the BBC's Editorial Guidelines on truthfulness, which reflects regulation 2.2 of the regulator's media standards.
"We have apologised for this and we agree with Ofcom's decision in its entirety. We will follow the penalty as soon as the timing and language are finalised."
