The British broadcaster committed a "significant breach" of media regulations by omitting to mention that the voice of a documentary about Gaza was the child of a Hamas representative, as ruled by regulatory body Ofcom.
An investigation by Ofcom into Gaza: How to Survive a Warzone has determined that the programme was "materially misleading".
The BBC's director general had earlier expressed regret, stating there had been "a significant failing in relation to truthfulness".
Ofcom has instructed the corporation to air a prime-time statement about its decisions.
"Since this amounts to a major infringement of our code, we are ordering the corporation to transmit a message of our conclusions against it on BBC Two at 21:00, with a schedule to be finalised," it said.
'Risk to Erode Credibility'
The watchdog's statement said: "Our investigation concluded that the documentary's failure to disclose that the narrator's father held a role in the Hamas-administered administration was materially misleading.
"It meant that the audience did not have vital facts which may have been highly relevant to their judgment of the narrator and the details he shared.
"Confidence is at the heart of the connection between a broadcaster and its public, especially for a public service broadcaster such as the BBC.
"This oversight had the potential to damage the significantly high levels of trust that audiences would have put in a factual film from the broadcaster about the Israel-Gaza war."
The programme was withdrawn from the BBC's streaming service in last February after the narrator's personal associations came to light, and in the month of July an corporation's own inquiry determined it infringed the broadcaster's editorial guidelines on truthfulness.
A BBC spokesperson said: "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 broadcaster's journalistic policies on truthfulness, which corresponds to regulation 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we accept the regulator's ruling in full. We will adhere to the sanction as soon as the timing and wording are confirmed."
