The British broadcaster engaged in a "significant breach" of industry standards by failing to disclose that the presenter of a programme about Gaza was the offspring of a Hamas representative, as ruled by UK media regulator Ofcom.
An inquiry by Ofcom into the programme Gaza: How to Survive a Warzone has determined that the documentary was "materially misleading".
The chief executive of the broadcaster had previously apologised, stating there had been "a serious error in relation to factual correctness".
The authority has directed the corporation to transmit a evening statement about its decisions.
"Given this constitutes a serious breach of our rules, we are instructing the BBC to air a announcement of our findings against it on the BBC's second channel at nine o'clock in the evening, with a timing to be determined," it said.
'Risk to Erode Confidence'
The watchdog's statement said: "Our investigation concluded that the programme's failure to disclose that the voice's father occupied a position in the Hamas-controlled administration was substantially inaccurate.
"Consequently that the viewers did not have critical information which may have been highly relevant to their judgment of the voice and the information he shared.
"Confidence is at the core of the connection between a television network and its viewers, particularly for a state-funded media outlet such as the British Broadcasting Corporation.
"This error had the risk to undermine the significantly high levels of confidence that audiences would have invested in a documentary produced by the BBC about the conflict in Gaza."
The programme was removed from iPlayer in last February after the presenter's personal associations emerged, and in July an broadcaster's internal assessment determined it violated the organization's editorial guidelines on truthfulness.
A BBC spokesperson said: "The regulator's decision is in agreement with the findings of Peter Johnston's review, that there was a serious error in the documentary in relation to the BBC's Editorial Guidelines on factual correctness, which reflects clause 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we agree with Ofcom's decision in full. We will comply with the penalty as soon as the timing and wording are confirmed."
