The public service broadcaster was found to have committed a "significant breach" of broadcasting rules by omitting to mention that the presenter of a programme about the Gaza conflict was the son of a Hamas administrator, according to regulatory body Ofcom.
An probe by the broadcasting watchdog into Gaza: How to Survive a Warzone has determined that the film was "substantially inaccurate".
The head of the BBC had already issued an apology, saying there had been "a serious error in relation to factual correctness".
The authority has directed the BBC to transmit a peak-time announcement about its conclusions.
"As this represents a serious breach of our regulations, we are directing the BBC to air a announcement of our conclusions against it on BBC2 at 21:00, with a timing to be determined," it said.
'Potential to Undermine Confidence'
The regulator's statement said: "The inquiry we conducted concluded that the documentary's lack of disclosure that the narrator's male guardian held a post in the Hamas-run administration was materially misleading.
"This implied that the public did not have vital facts which may have been very significant to their evaluation of the voice and the information he presented.
"Credibility is at the core of the connection between a television network and its public, especially for a state-funded media outlet such as the BBC.
"This failing had the potential to erode the very considerable levels of credibility that audiences would have placed in a BBC factual programme about the conflict in Gaza."
The documentary was pulled from iPlayer in February after the presenter's family links came to light, and in July an broadcaster's internal assessment found it breached the broadcaster's editorial guidelines on accuracy.
A BBC spokesperson stated: "The Ofcom ruling is in line with the conclusions of the corporation's inquiry, that there was a major oversight in the film in relation to the corporation's content standards on truthfulness, which reflects clause 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we agree with Ofcom's decision in complete. We will follow the directive as soon as the date and wording are finalised."
