The public service broadcaster committed a "significant breach" of industry standards by omitting to mention that the presenter of a documentary about Gaza was the offspring of a Hamas official, as determined by regulatory body Ofcom.
An investigation by the broadcasting watchdog into Gaza: How to Survive a Warzone has found that the film was "substantially inaccurate".
The chief executive of the broadcaster had earlier expressed regret, stating there had been "a significant failing in relation to factual correctness".
The regulator has instructed the BBC to air a peak-time announcement about its findings.
"Since this amounts to a significant violation of our regulations, we are instructing the corporation to broadcast a message of our determinations against it on BBC Two at nine o'clock in the evening, with a date to be confirmed," the statement read.
'Possibility to Damage Trust'
The authority's announcement stated: "Our investigation found that the programme's omission to reveal that the narrator's parent served in a role in the Hamas-controlled authority was materially misleading.
"Consequently that the viewers did not have critical information which may have been highly relevant to their judgment of the presenter and the information he shared.
"Trust is at the heart of the bond between a media organization and its viewers, especially for a state-funded media outlet such as the BBC.
"This failing had the possibility to erode the exceptionally strong levels of confidence that audiences would have invested in a BBC factual programme about the Gaza conflict."
The film was removed from the BBC's streaming service in last February after the narrator's family links emerged, and in the month of July an corporation's own inquiry concluded it violated the corporation's content policies on truthfulness.
A BBC spokesperson commented: "The Ofcom ruling is in accordance with the conclusions of the internal assessment, that there was a major oversight in the programme in relation to the corporation's content standards on truthfulness, which reflects regulation 2.2 of the regulator's media standards.
"We expressed regret for this and we accept Ofcom's decision in full. We will comply with the sanction as soon as the date and wording are finalised."
