The public service broadcaster committed a "major breach" of broadcasting rules by not revealing that the presenter of a programme about Gaza was the child of a Hamas official, as determined by regulatory body Ofcom.
An probe by the media regulator into Gaza: How to Survive a Warzone has concluded that the programme was "substantially inaccurate".
The head of the BBC had already issued an apology, stating there had been "a significant failing in relation to truthfulness".
The authority has directed the corporation to air a evening announcement about its findings.
"As this represents a serious breach of our rules, we are directing the BBC to transmit a statement of our determinations against it on the BBC's second channel at nine o'clock in the evening, with a date to be determined," it said.
'Potential to Damage Credibility'
The watchdog's statement declared: "The inquiry we conducted found that the programme's lack of disclosure that the narrator's male guardian held a position in the Hamas-controlled administration was significantly deceptive.
"It meant that the viewers did not have essential details which may have been very significant to their assessment of the presenter and the content he shared.
"Confidence is at the core of the connection between a media organization and its public, especially for a national broadcasting corporation such as the BBC.
"This oversight had the potential to erode the exceptionally strong levels of credibility that viewers would have invested in a BBC factual programme about the conflict in Gaza."
The documentary was withdrawn from the online platform in the month of February after the presenter's familial connections came to light, and in July an internal BBC review concluded it infringed the organization's content policies on factual correctness.
A BBC spokesperson said: "The regulator's decision is in accordance with the conclusions of the corporation's inquiry, that there was a major oversight in the documentary in relation to the broadcaster's journalistic policies on truthfulness, which reflects regulation 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we accept Ofcom's decision in full. We will adhere to the penalty as soon as the schedule and wording are confirmed."
