The public service broadcaster was found to have committed a "major breach" of media regulations by failing to disclose that the presenter of a programme about the Gaza conflict was the offspring of a Hamas official, as determined by regulatory body Ofcom.
An probe by Ofcom into Gaza: How to Survive a Warzone has concluded that the documentary was "substantially inaccurate".
The chief executive of the broadcaster had previously apologised, noting there had been "a serious error in relation to truthfulness".
The authority has directed the BBC to transmit a evening statement about its findings.
"Given this constitutes a significant violation of our code, we are instructing the corporation to broadcast a message of our findings against it on BBC Two at 21:00, with a schedule to be confirmed," the statement read.
'Risk to Damage Credibility'
The watchdog's announcement said: "Our investigation found that the programme's omission to reveal that the narrator's parent held a post in the Hamas-run government was substantially inaccurate.
"This implied that the public did not have essential details which may have been highly relevant to their assessment of the voice and the information he shared.
"Trust is at the core of the connection between a media organization and its public, notably for a public service broadcaster such as the BBC.
"This failing had the possibility to erode the significantly high amounts of trust that viewers would have placed in a documentary produced by the BBC about the Gaza conflict."
The documentary was withdrawn from the BBC's streaming service in the month of February after the presenter's familial connections came to light, and in July an broadcaster's internal assessment determined it violated the corporation's content policies on truthfulness.
A BBC spokesperson stated: "The authority's determination is in accordance with the results of Peter Johnston's review, that there was a major oversight in the film in relation to the corporation's content standards on factual correctness, which corresponds to regulation 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we agree with the regulator's ruling in complete. We will follow the penalty as soon as the timing and wording are confirmed."
