The British broadcaster committed a "significant breach" of industry standards by omitting to mention that the presenter of a film about the Gaza conflict was the offspring of a Hamas representative, as determined by regulatory body Ofcom.
An investigation by Ofcom into Gaza: How to Survive a Warzone has concluded that the programme was "substantially inaccurate".
The head of the BBC had previously apologised, saying there had been "a major oversight in relation to truthfulness".
The authority has directed the broadcaster to air a prime-time announcement about its findings.
"As this represents a significant violation of our code, we are instructing the BBC to air a announcement of our conclusions against it on BBC Two at 21:00, with a schedule to be confirmed," the regulator stated.
'Possibility to Erode Trust'
The watchdog's report said: "The inquiry we conducted concluded that the film's lack of disclosure that the presenter's father held a role in the Hamas-controlled authority was significantly deceptive.
"It meant that the audience did not have vital facts which may have been highly relevant to their evaluation of the presenter and the details he provided.
"Credibility is at the heart of the connection between a broadcaster and its public, particularly for a public service broadcaster such as the public broadcaster.
"This error had the potential to undermine the very considerable amounts of trust that audiences would have placed in a documentary produced by the BBC about the conflict in Gaza."
The programme was withdrawn from the BBC's streaming service in last February after the narrator's family links were revealed, and in the month of July an corporation's own inquiry determined it infringed the broadcaster's content policies on factual correctness.
A representative for the broadcaster stated: "The Ofcom ruling is in accordance with the findings of the corporation's inquiry, that there was a significant failing in the documentary in relation to the BBC's Editorial Guidelines on truthfulness, which reflects regulation 2.2 of the regulator's media standards.
"We issued an apology for this and we accept the regulator's ruling in full. We will comply with the penalty as soon as the date and wording are confirmed."
