The BBC was found to have committed a "major breach" of broadcasting rules by failing to disclose that the voice of a film about Gaza was the offspring of a Hamas representative, as determined by regulatory body Ofcom.
An probe by the broadcasting watchdog into the documentary titled Gaza: How to Survive a Warzone has determined that the documentary was "materially misleading".
The chief executive of the broadcaster had earlier expressed regret, noting there had been "a significant failing in relation to factual correctness".
The regulator has instructed the BBC to transmit a evening statement about its conclusions.
"As this represents a major infringement of our rules, we are ordering the BBC to air a announcement of our determinations against it on the BBC's second channel at 9pm, with a date to be confirmed," it said.
'Risk to Erode Credibility'
The watchdog's announcement stated: "The inquiry we conducted concluded that the film's failure to disclose that the narrator's father served in a position in the Hamas-controlled authority was significantly deceptive.
"It meant that the public did not have critical information which may have been very significant to their judgment of the voice and the content he provided.
"Confidence is at the heart of the connection between a television network and its viewers, particularly for a state-funded media outlet such as the British Broadcasting Corporation.
"This oversight had the potential to erode the very considerable amounts of credibility that the public would have placed in a BBC factual programme about the conflict in Gaza."
The programme was withdrawn from iPlayer in last February after the narrator's personal associations were revealed, and in this past July an corporation's own inquiry found it breached the corporation's journalistic standards on factual correctness.
A corporation official said: "The Ofcom ruling is in accordance with the findings of the corporation's inquiry, that there was a significant failing in the film in relation to the broadcaster's journalistic policies on factual correctness, which reflects clause 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we agree with the authority's determination in complete. We will comply with the sanction as soon as the timing and wording are confirmed."
