The public service broadcaster was found to have committed a "significant breach" of industry standards by failing to disclose that the narrator of a film about Gaza was the child of a Hamas representative, according to regulatory body Ofcom.
An inquiry by the broadcasting watchdog into Gaza: How to Survive a Warzone has determined that the programme was "materially misleading".
The BBC's director general had already issued an apology, saying there had been "a major oversight in relation to factual correctness".
The authority has ordered the broadcaster to transmit a evening announcement about its conclusions.
"As this represents a serious breach of our rules, we are directing the corporation to broadcast a announcement of our findings against it on BBC2 at 9pm, with a date to be confirmed," it said.
'Possibility to Undermine Trust'
The regulator's announcement declared: "The inquiry we conducted concluded that the programme's failure to disclose that the narrator's father served in a post in the Hamas-run government was materially misleading.
"It meant that the audience did not have critical information which may have been highly relevant to their assessment of the narrator and the information he shared.
"Confidence is at the heart of the connection between a television network and its viewers, particularly for a public service broadcaster such as the public broadcaster.
"This error had the risk to erode the very considerable levels of trust that viewers would have invested in a documentary produced by the BBC about the Gaza conflict."
The documentary was removed from iPlayer in February after the narrator's family links emerged, and in the month of July an broadcaster's internal assessment concluded it breached the corporation's editorial guidelines on factual correctness.
A corporation official said: "The regulator's decision is in agreement with the results of Peter Johnston's review, that there was a serious error in the film in relation to the corporation's content standards on truthfulness, which reflects Rule 2.2 of Ofcom's Broadcasting Code.
"We expressed regret for this and we accept the regulator's ruling in complete. We will adhere to the sanction as soon as the schedule and language are confirmed."
