The public service broadcaster engaged in a "major breach" of broadcasting rules by omitting to mention that the presenter of a programme about the Gaza conflict was the offspring of a Hamas official, according to British broadcasting authority Ofcom.
An probe by the broadcasting watchdog into Gaza: How to Survive a Warzone has determined that the documentary was "significantly deceptive".
The head of the BBC had already issued an apology, saying there had been "a serious error in relation to accuracy".
The authority has instructed the broadcaster to broadcast a peak-time statement about its findings.
"Given this constitutes a major infringement of our rules, we are instructing the broadcaster to broadcast a announcement of our determinations against it on the BBC's second channel at nine o'clock in the evening, with a timing to be confirmed," the statement read.
'Possibility to Undermine Credibility'
The regulator's announcement declared: "Our probe found that the programme's omission to reveal that the presenter's parent occupied a position in the Hamas-administered government was materially misleading.
"Consequently that the viewers did not have critical information which may have been extremely pertinent to their assessment of the narrator and the information he presented.
"Credibility is at the center of the bond between a media organization and its audience, particularly for a state-funded media outlet such as the public broadcaster.
"This error had the risk to erode the very considerable levels of credibility that the public would have placed in a BBC factual programme about the conflict in Gaza."
The documentary was withdrawn from the BBC's streaming service in last February after the presenter's familial connections were revealed, and in July an internal BBC review determined it breached the organization's journalistic standards on truthfulness.
A representative for the broadcaster commented: "The authority's determination is in accordance with the findings of the corporation's inquiry, that there was a serious error in the programme in relation to the BBC's Editorial Guidelines on accuracy, which reflects clause 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we comply with the regulator's ruling in complete. We will comply with the penalty as soon as the schedule and wording are determined."
