The BBC engaged in a "significant breach" of industry standards by not revealing that the voice of a documentary about the Gaza conflict was the child of a Hamas official, as determined by UK media regulator Ofcom.
An inquiry by the broadcasting watchdog into the documentary titled Gaza: How to Survive a Warzone has found that the film was "significantly deceptive".
The head of the BBC had earlier expressed regret, stating there had been "a serious error in relation to accuracy".
Ofcom has ordered the corporation to air a peak-time statement about its conclusions.
"Given this constitutes a major infringement of our code, we are instructing the BBC to transmit a statement of our findings against it on the BBC's second channel at nine o'clock in the evening, with a schedule to be finalised," the statement read.
'Possibility to Undermine Trust'
The watchdog's announcement declared: "Our probe determined that the documentary's lack of disclosure that the voice's parent occupied a post in the Hamas-run administration was materially misleading.
"This implied that the viewers did not have essential details which may have been highly relevant to their assessment of the presenter and the information he presented.
"Confidence is at the heart of the bond between a broadcaster and its viewers, particularly for a public service broadcaster such as the BBC.
"This error had the risk to damage the exceptionally strong degrees of credibility that the public would have invested in a factual film from the broadcaster about the conflict in Gaza."
The documentary was withdrawn from the BBC's streaming service in last February after the presenter's personal associations came to light, and in this past July an internal BBC review determined it violated the broadcaster's content policies on factual correctness.
A corporation official said: "The regulator's decision is in agreement with the results of Peter Johnston's review, that there was a significant failing in the programme in relation to the broadcaster's journalistic policies on factual correctness, 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 follow the penalty as soon as the date and wording are finalised."
