The BBC was found to have committed a "major breach" of industry standards by failing to disclose that the voice of a programme about the Gaza conflict was the child of a Hamas representative, according to UK media regulator Ofcom.
An inquiry by Ofcom into Gaza: How to Survive a Warzone has found that the programme was "substantially inaccurate".
The chief executive of the broadcaster had previously apologised, stating there had been "a serious error in relation to truthfulness".
The authority has ordered the BBC to transmit a prime-time declaration about its decisions.
"As this represents a major infringement of our regulations, we are directing the BBC to transmit a announcement of our findings against it on the BBC's second channel at 21:00, with a schedule to be finalised," the statement read.
'Possibility to Erode Trust'
The authority's report stated: "The inquiry we conducted determined that the documentary's lack of disclosure that the voice's parent held a post in the Hamas-administered government was significantly deceptive.
"Consequently that the viewers did not have vital facts which may have been highly relevant to their assessment of the narrator and the details he provided.
"Trust is at the core of the bond between a television network and its audience, especially for a state-funded media outlet such as the British Broadcasting Corporation.
"This error had the possibility to undermine the significantly high amounts of confidence that audiences would have invested in a factual film from the broadcaster about the Israel-Gaza war."
The documentary was removed from the online platform in last February after the presenter's personal associations came to light, and in this past July an corporation's own inquiry concluded it violated the broadcaster's content policies on factual correctness.
A corporation official commented: "The authority's determination is in line with the conclusions of the internal assessment, that there was a serious error in the film in relation to the corporation's content standards on truthfulness, which aligns with regulation 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we accept the authority's determination in complete. We will follow the penalty as soon as the schedule and language are confirmed."
