The British broadcaster was found to have committed a "significant breach" of broadcasting rules by failing to disclose that the narrator of a film about Gaza was the child of a Hamas representative, according to regulatory body Ofcom.
An investigation by Ofcom into Gaza: How to Survive a Warzone has determined that the film was "significantly deceptive".
The chief executive of the broadcaster had already issued an apology, saying there had been "a major oversight in relation to truthfulness".
Ofcom has instructed the broadcaster to air a evening announcement about its findings.
"As this represents a significant violation of our rules, we are ordering the BBC to transmit a announcement of our determinations against it on BBC2 at 21:00, with a timing to be confirmed," the statement read.
'Risk to Undermine Confidence'
The watchdog's statement stated: "The inquiry we conducted concluded that the film's lack of disclosure that the narrator's male guardian occupied a role in the Hamas-run government was substantially inaccurate.
"It meant that the public did not have vital facts which may have been very significant to their assessment of the presenter and the details he shared.
"Trust is at the center of the relationship between a broadcaster and its public, notably for a public service broadcaster such as the public broadcaster.
"This error had the risk to erode the exceptionally strong amounts of trust that audiences would have invested in a BBC factual programme about the conflict in Gaza."
The documentary was withdrawn from iPlayer in the month of February after the presenter's personal associations emerged, and in July an internal BBC review concluded it infringed the organization's editorial guidelines on factual correctness.
A BBC spokesperson stated: "The regulator's decision is in line with the conclusions of Peter Johnston's review, that there was a significant failing in the programme in relation to the broadcaster's journalistic policies on factual correctness, which reflects Rule 2.2 of the regulator's media standards.
"We issued an apology for this and we accept the authority's determination in complete. We will follow the penalty as soon as the date and wording are confirmed."
