The public service broadcaster committed a "significant breach" of broadcasting rules by failing to disclose that the voice of a film about Gaza was the child of a Hamas administrator, according to UK media regulator Ofcom.
An investigation by the media regulator into the documentary titled Gaza: How to Survive a Warzone has concluded that the film was "materially misleading".
The BBC's director general had previously apologised, noting there had been "a serious error in relation to truthfulness".
The regulator has instructed the corporation to air a peak-time declaration about its decisions.
"As this represents a significant violation of our regulations, we are directing the corporation to air a announcement of our conclusions against it on BBC2 at nine o'clock in the evening, with a timing to be confirmed," the statement read.
'Possibility to Undermine Credibility'
The authority's report said: "Our probe concluded that the programme's lack of disclosure that the narrator's parent held a position in the Hamas-controlled administration was significantly deceptive.
"This implied that the audience did not have critical information which may have been extremely pertinent to their assessment of the voice and the content he shared.
"Trust is at the core of the connection between a media organization and its public, particularly for a state-funded media outlet such as the British Broadcasting Corporation.
"This error had the possibility to damage the very considerable levels of credibility that the public would have put in a BBC factual programme about the conflict in Gaza."
The film was pulled from the BBC's streaming service in last February after the presenter's family links emerged, and in this past July an internal BBC review found it infringed the organization's editorial guidelines on truthfulness.
A BBC spokesperson said: "The authority's determination is in line with the results of the internal assessment, that there was a serious error in the programme in relation to the BBC's Editorial Guidelines on factual correctness, which corresponds to Rule 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 adhere to the sanction as soon as the schedule and wording are confirmed."