The BBC was found to have committed a "major breach" of industry standards by omitting to mention that the voice of a film about the Gaza situation was the child of a Hamas administrator, as determined by regulatory body Ofcom.
An investigation by Ofcom into the documentary titled Gaza: How to Survive a Warzone has determined that the programme was "significantly deceptive".
The BBC's director general had earlier expressed regret, noting there had been "a significant failing in relation to factual correctness".
The regulator has instructed the BBC to air a evening declaration about its conclusions.
"Given this constitutes a significant violation of our rules, we are instructing the corporation to air a message of our determinations against it on the BBC's second channel at nine o'clock in the evening, with a timing to be finalised," it said.
'Risk to Damage Trust'
The regulator's report stated: "The inquiry we conducted concluded that the programme's failure to disclose that the narrator's parent occupied a role in the Hamas-administered administration was materially misleading.
"Consequently that the public did not have essential details which may have been highly relevant to their evaluation of the presenter and the content he shared.
"Confidence is at the core of the connection between a television network and its audience, particularly for a state-funded media outlet such as the British Broadcasting Corporation.
"This error had the possibility to erode the significantly high levels of credibility that the public would have placed in a documentary produced by the BBC about the Israel-Gaza war."
The documentary was removed from the online platform in February after the narrator's personal associations emerged, and in July an broadcaster's internal assessment found it infringed the corporation's content policies on accuracy.
A BBC spokesperson said: "The authority's determination is in line with the conclusions of Peter Johnston's review, that there was a significant failing in the film in relation to the BBC's Editorial Guidelines on factual correctness, which reflects clause 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we accept the regulator's ruling in its entirety. We will follow the directive as soon as the schedule and wording are determined."
