The public service broadcaster was found to have committed a "major breach" of media regulations by not revealing that the narrator of a documentary about the Gaza conflict was the son of a Hamas representative, according to UK media regulator Ofcom.
An probe by Ofcom into Gaza: How to Survive a Warzone has found that the documentary was "significantly deceptive".
The BBC's director general had earlier expressed regret, saying there had been "a major oversight in relation to accuracy".
Ofcom has directed the corporation to broadcast a prime-time announcement about its conclusions.
"Given this constitutes a major infringement of our rules, we are instructing the corporation to transmit a message of our determinations against it on BBC2 at nine o'clock in the evening, with a date to be finalised," it said.
'Risk to Undermine Credibility'
The watchdog's report said: "Our probe concluded that the film's lack of disclosure that the voice's father served in a role in the Hamas-run authority was materially misleading.
"It meant that the public did not have essential details which may have been extremely pertinent to their judgment of the narrator and the information he shared.
"Trust is at the core of the connection between a media organization and its public, notably for a state-funded media outlet such as the public broadcaster.
"This oversight had the risk to erode the exceptionally strong degrees of trust that the public would have invested in a BBC factual programme about the Gaza conflict."
The film was withdrawn from the BBC's streaming service in last February after the presenter's personal associations were revealed, and in July an corporation's own inquiry concluded it breached the corporation's journalistic standards on truthfulness.
A representative for the broadcaster commented: "The Ofcom ruling is in agreement with the results of the corporation's inquiry, that there was a significant failing in the film in relation to the corporation's content standards on accuracy, which aligns with clause 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we comply with Ofcom's decision in its entirety. We will follow the penalty as soon as the timing and language are determined."
