The BBC committed a "serious breach" of broadcasting rules by not revealing that the voice of a documentary about the Gaza situation was the offspring of a Hamas administrator, according to regulatory body Ofcom.
An probe by the media regulator into the programme Gaza: How to Survive a Warzone has concluded that the documentary was "significantly deceptive".
The chief executive of the broadcaster had already issued an apology, stating there had been "a serious error in relation to accuracy".
Ofcom has directed the BBC to transmit a evening statement about its findings.
"Given this constitutes a major infringement of our code, we are ordering the corporation to air a message of our findings against it on BBC2 at 21:00, with a timing to be finalised," the regulator stated.
The watchdog's report said: "The inquiry we conducted found that the documentary's lack of disclosure that the voice's parent served in a role in the Hamas-run government was significantly deceptive.
"It meant that the public did not have vital facts which may have been very significant to their assessment of the voice and the details he shared.
"Credibility is at the heart of the relationship between a television network and its viewers, especially for a public service broadcaster such as the British Broadcasting Corporation.
"This failing had the potential to damage the significantly high degrees of confidence that the public would have invested in a factual film from the broadcaster about the Israel-Gaza war."
The film was removed from iPlayer in February after the presenter's personal associations were revealed, and in the month of July an corporation's own inquiry found it infringed the corporation's editorial guidelines on truthfulness.
A representative for the broadcaster said: "The Ofcom ruling is in accordance with the conclusions of Peter Johnston's review, that there was a significant failing in the programme in relation to the corporation's content standards on factual correctness, which aligns with regulation 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we comply with Ofcom's decision in complete. We will comply with the sanction as soon as the timing and language are determined."
Eleanor Hayes is a data scientist and business analyst with over a decade of experience in transforming raw data into actionable insights.