The public service broadcaster was found to have committed a "significant breach" of broadcasting rules by omitting to mention that the voice of a documentary about the Gaza conflict was the child of a Hamas official, according to regulatory body Ofcom.
An probe by Ofcom into Gaza: How to Survive a Warzone has found that the film was "substantially inaccurate".
The BBC's director general had already issued an apology, saying there had been "a serious error in relation to truthfulness".
The authority has instructed the corporation to broadcast a peak-time declaration about its findings.
"Since this amounts to a major infringement of our regulations, we are directing the BBC to broadcast a announcement of our determinations against it on BBC2 at nine o'clock in the evening, with a timing to be finalised," it said.
'Potential to Erode Confidence'
The authority's statement stated: "Our probe determined that the film's failure to disclose that the voice's father served in a post in the Hamas-run authority was materially misleading.
"This implied that the audience did not have vital facts which may have been highly relevant to their evaluation of the narrator and the information he shared.
"Confidence is at the core of the connection between a television network and its public, notably for a state-funded media outlet such as the public broadcaster.
"This oversight had the risk to erode the exceptionally strong amounts of credibility that viewers would have placed in a factual film from the broadcaster about the Gaza conflict."
The documentary was removed from the BBC's streaming service in February after the presenter's family links were revealed, and in this past July an internal BBC review concluded it violated the organization's editorial guidelines on truthfulness.
A representative for the broadcaster stated: "The authority's determination is in line with the findings of the corporation's inquiry, that there was a serious error in the programme in relation to the corporation's content standards on truthfulness, which corresponds to regulation 2.2 of the regulator's media standards.
"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 date and wording are finalised."
