The BBC engaged in a "major breach" of industry standards by omitting to mention that the narrator of a documentary about the Gaza conflict was the son of a Hamas official, as determined by regulatory body Ofcom.
An investigation by the broadcasting watchdog into the programme Gaza: How to Survive a Warzone has found that the documentary was "substantially inaccurate".
The BBC's director general had earlier expressed regret, saying there had been "a significant failing in relation to truthfulness".
Ofcom has instructed the BBC to broadcast a peak-time statement about its conclusions.
"Given this constitutes a serious breach of our rules, we are directing the corporation to broadcast a statement of our findings against it on BBC2 at nine o'clock in the evening, with a date to be confirmed," the statement read.
'Possibility to Undermine Trust'
The watchdog's statement stated: "The inquiry we conducted concluded that the programme's lack of disclosure that the presenter's father occupied a position in the Hamas-run authority was materially misleading.
"Consequently that the public did not have vital facts which may have been very significant to their evaluation of the presenter and the information he shared.
"Credibility is at the center of the bond between a television network and its viewers, particularly for a public service broadcaster such as the British Broadcasting Corporation.
"This error had the potential to erode the significantly high levels of credibility that the public would have invested in a BBC factual programme about the Israel-Gaza war."
The programme was removed from the online platform in the month of February after the narrator's personal associations were revealed, and in the month of July an broadcaster's internal assessment found it violated the organization's editorial guidelines on accuracy.
A corporation official commented: "The Ofcom ruling is in accordance with the conclusions of Peter Johnston's review, that there was a major oversight in the documentary in relation to the BBC's Editorial Guidelines on accuracy, which corresponds to clause 2.2 of the regulator's media standards.
"We expressed regret for this and we agree with the authority's determination in full. We will comply with the penalty as soon as the schedule and wording are finalised."
