The public service broadcaster was found to have committed a "significant breach" of broadcasting rules by not revealing that the voice of a documentary about the Gaza conflict was the child of a Hamas official, according to British broadcasting authority Ofcom.
An probe by the media regulator into the programme Gaza: How to Survive a Warzone has found that the documentary was "significantly deceptive".
The BBC's director general had earlier expressed regret, saying there had been "a major oversight in relation to factual correctness".
Ofcom has directed the BBC to broadcast a evening statement about its decisions.
"Since this amounts to a significant violation of our rules, we are ordering the corporation to broadcast a statement of our determinations against it on the BBC's second channel at nine o'clock in the evening, with a schedule to be finalised," the statement read.
'Potential to Damage Confidence'
The regulator's announcement said: "The inquiry we conducted determined that the programme's failure to disclose that the voice's father served in a position in the Hamas-controlled government was significantly deceptive.
"It meant that the public did not have vital facts which may have been highly relevant to their judgment of the presenter and the details he presented.
"Trust is at the heart of the bond between a broadcaster and its viewers, especially for a state-funded media outlet such as the BBC.
"This failing had the risk to undermine the exceptionally strong levels of credibility that audiences would have invested in a documentary produced by the BBC about the Israel-Gaza war."
The documentary was removed from iPlayer in February after the presenter's family links emerged, and in this past July an corporation's own inquiry concluded it violated the broadcaster's content policies on factual correctness.
A corporation official stated: "The authority's determination is in agreement with the results of Peter Johnston's review, that there was a major oversight in the documentary in relation to the broadcaster's journalistic policies on factual correctness, which aligns with clause 2.2 of Ofcom's Broadcasting Code.
"We expressed regret for this and we accept the regulator's ruling in its entirety. We will comply with the sanction as soon as the date and wording are determined."
