The public service broadcaster engaged in a "significant breach" of industry standards by omitting to mention that the narrator of a programme about Gaza was the child of a Hamas official, as determined by British broadcasting authority Ofcom.
An inquiry by the broadcasting watchdog into the programme Gaza: How to Survive a Warzone has determined that the programme was "substantially inaccurate".
The head of the BBC had previously apologised, saying there had been "a serious error in relation to accuracy".
Ofcom has directed the corporation to air a peak-time announcement about its decisions.
"Since this amounts to a serious breach of our rules, we are instructing the corporation to transmit a statement of our findings against it on BBC Two at 9pm, with a date to be confirmed," the statement read.
'Risk to Undermine Credibility'
The authority's announcement said: "The inquiry we conducted determined that the documentary's lack of disclosure that the narrator's father served in a position in the Hamas-administered authority was substantially inaccurate.
"This implied that the public did not have vital facts which may have been highly relevant to their assessment of the presenter and the information he provided.
"Credibility is at the center of the relationship between a television network and its audience, notably for a state-funded media outlet such as the public broadcaster.
"This error had the possibility to undermine the very considerable amounts of confidence that the public would have put in a BBC factual programme about the conflict in Gaza."
The film was withdrawn from the online platform in last February after the presenter's personal associations were revealed, and in July an broadcaster's internal assessment concluded it breached the corporation's content policies on truthfulness.
A BBC spokesperson stated: "The regulator's decision is in accordance with the conclusions of Peter Johnston's review, that there was a serious error in the programme in relation to the corporation's content standards on truthfulness, which reflects regulation 2.2 of Ofcom's Broadcasting Code.
"We expressed regret for this and we comply with Ofcom's decision in its entirety. We will comply with the penalty as soon as the date and wording are confirmed."
