The public service broadcaster was found to have committed a "significant breach" of media regulations by not revealing that the presenter of a film about Gaza was the son of a Hamas official, according to UK media regulator Ofcom.
An investigation by the broadcasting watchdog into Gaza: How to Survive a Warzone has concluded that the documentary was "materially misleading".
The head of the BBC had earlier expressed regret, noting there had been "a serious error in relation to factual correctness".
The authority has instructed the broadcaster to broadcast a evening statement about its findings.
"As this represents a major infringement of our code, we are directing the BBC to air a message of our conclusions against it on the BBC's second channel at 9pm, with a timing to be determined," it said.
'Potential to Damage Trust'
The authority's announcement stated: "Our probe determined that the documentary's failure to disclose that the voice's father served in a post in the Hamas-administered government was significantly deceptive.
"This implied that the audience did not have essential details which may have been extremely pertinent to their evaluation of the voice and the content he provided.
"Credibility is at the heart of the relationship between a television network and its audience, particularly for a public service broadcaster such as the BBC.
"This failing had the risk to erode the exceptionally strong levels of credibility that audiences would have invested in a factual film from the broadcaster about the Gaza conflict."
The documentary was withdrawn from iPlayer in the month of February after the narrator's personal associations were revealed, and in July an broadcaster's internal assessment found it infringed the corporation's content policies on factual correctness.
A corporation official said: "The authority's determination is in line with the conclusions of the internal assessment, that there was a serious error in the documentary in relation to the BBC's Editorial Guidelines on truthfulness, which reflects Rule 2.2 of the regulator's media standards.
"We issued an apology for this and we comply with the regulator's ruling in its entirety. We will adhere to the sanction as soon as the schedule and wording are confirmed."
