The British broadcaster engaged in a "significant breach" of industry standards by omitting to mention that the voice of a programme about the Gaza situation was the son of a Hamas representative, as ruled by regulatory body Ofcom.
An probe by Ofcom into the programme Gaza: How to Survive a Warzone has found that the programme was "materially misleading".
The head of the BBC had already issued an apology, saying there had been "a major oversight in relation to factual correctness".
Ofcom has ordered the BBC to air a evening statement about its findings.
"Given this constitutes a significant violation of our code, we are ordering the corporation to transmit a announcement of our conclusions against it on BBC2 at 21:00, with a schedule to be determined," the regulator stated.
'Possibility to Damage Credibility'
The authority's report stated: "Our probe concluded that the programme's omission to reveal that the narrator's father held a role in the Hamas-controlled administration was significantly deceptive.
"Consequently that the viewers did not have critical information which may have been very significant to their assessment of the narrator and the information he presented.
"Credibility is at the core of the relationship between a broadcaster and its public, particularly for a national broadcasting corporation such as the public broadcaster.
"This error had the risk to undermine the very considerable degrees of trust that viewers would have invested in a factual film from the broadcaster about the Gaza conflict."
The film was withdrawn from iPlayer in the month of February after the presenter's personal associations emerged, and in the month of July an corporation's own inquiry concluded it violated the broadcaster's editorial guidelines on factual correctness.
A BBC spokesperson commented: "The Ofcom ruling is in accordance with the findings of Peter Johnston's review, that there was a significant failing in the documentary in relation to the broadcaster's journalistic policies on factual correctness, which corresponds to Rule 2.2 of the regulator's media standards.
"We expressed regret for this and we agree with Ofcom's decision in its entirety. We will follow the penalty as soon as the schedule and language are finalised."
