The public service broadcaster committed a "significant breach" of media regulations by not revealing that the presenter of a film about the Gaza conflict was the son of a Hamas representative, as ruled by regulatory body Ofcom.
An investigation by the media regulator into Gaza: How to Survive a Warzone has found that the programme was "materially misleading".
The BBC's director general had earlier expressed regret, noting there had been "a major oversight in relation to truthfulness".
The authority has ordered the corporation to air a peak-time declaration about its conclusions.
"As this represents a significant violation of our rules, we are directing the broadcaster to air a message of our conclusions against it on BBC Two at 21:00, with a schedule to be determined," the regulator stated.
'Possibility to Erode Credibility'
The watchdog's announcement said: "The inquiry we conducted determined that the film's lack of disclosure that the voice's male guardian held a role in the Hamas-run administration was materially misleading.
"It meant that the public did not have vital facts which may have been extremely pertinent to their evaluation of the presenter and the content he provided.
"Trust is at the core of the relationship between a television network and its viewers, especially for a public service broadcaster such as the British Broadcasting Corporation.
"This oversight had the potential to damage the very considerable degrees of confidence that the public would have placed in a factual film from the broadcaster about the Israel-Gaza war."
The documentary was removed from iPlayer in the month of February after the presenter's personal associations emerged, and in July an corporation's own inquiry determined it breached the broadcaster's content policies on truthfulness.
A representative for the broadcaster said: "The authority's determination is in agreement with the conclusions of Peter Johnston's review, that there was a significant failing in the film in relation to the broadcaster's journalistic policies on factual correctness, which corresponds to regulation 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we agree with the regulator's ruling in its entirety. We will follow the penalty as soon as the timing and wording are determined."
