The BBC was found to have committed a "significant breach" of industry standards by omitting to mention that the narrator of a programme about the Gaza situation was the son of a Hamas official, according to regulatory body Ofcom.
An probe by the media regulator into Gaza: How to Survive a Warzone has found that the documentary was "substantially inaccurate".
The chief executive of the broadcaster had previously apologised, stating there had been "a major oversight in relation to accuracy".
The authority has ordered the BBC to air a evening announcement about its conclusions.
"As this represents a serious breach of our regulations, we are directing the BBC to broadcast a message of our findings against it on BBC Two at 9pm, with a date to be finalised," the regulator stated.
'Possibility to Undermine Confidence'
The authority's announcement stated: "Our investigation found that the documentary's failure to disclose that the presenter's male guardian served in a position in the Hamas-controlled government was substantially inaccurate.
"It meant that the public did not have essential details which may have been very significant to their judgment of the narrator and the details he presented.
"Credibility is at the center of the bond between a television network and its audience, notably for a public service broadcaster such as the British Broadcasting Corporation.
"This oversight had the possibility to erode the exceptionally strong amounts of credibility that viewers would have invested in a documentary produced by the BBC about the Gaza conflict."
The programme was pulled from iPlayer in last February after the presenter's personal associations emerged, and in July an broadcaster's internal assessment concluded it infringed the broadcaster's content policies on truthfulness.
A corporation official said: "The authority's determination is in line with the conclusions of Peter Johnston's review, that there was a serious error in the documentary in relation to the BBC's Editorial Guidelines on accuracy, which corresponds to clause 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we comply with Ofcom's decision in complete. We will adhere to the directive as soon as the date and wording are determined."
