The BBC was found to have committed a "serious breach" of industry standards by not revealing that the presenter of a film about the Gaza conflict was the son of a Hamas official, according to British broadcasting authority Ofcom.
An inquiry by the media regulator into Gaza: How to Survive a Warzone has determined that the programme was "materially misleading".
The BBC's director general had previously apologised, stating there had been "a major oversight in relation to factual correctness".
Ofcom has directed the BBC to air a evening announcement about its conclusions.
"Since this amounts to a significant violation of our rules, we are instructing the BBC to transmit a announcement of our determinations against it on BBC2 at nine o'clock in the evening, with a schedule to be determined," the statement read.
'Risk to Erode Trust'
The regulator's statement declared: "Our investigation found that the film's omission to reveal that the voice's male guardian served in a position in the Hamas-run government was significantly deceptive.
"This implied that the viewers did not have critical information which may have been extremely pertinent to their judgment of the presenter and the information he presented.
"Credibility is at the center of the bond between a media organization and its viewers, particularly for a public service broadcaster such as the public broadcaster.
"This failing had the potential to damage the very considerable amounts of trust that viewers would have placed in a BBC factual programme about the conflict in Gaza."
The documentary was removed from iPlayer in February after the presenter's personal associations emerged, and in July an corporation's own inquiry found it infringed the corporation's journalistic standards on factual correctness.
A BBC spokesperson commented: "The regulator's decision is in accordance with the findings of the corporation's inquiry, that there was a serious error in the film in relation to the corporation's content standards on accuracy, which corresponds to regulation 2.2 of Ofcom's Broadcasting Code.
"We expressed regret for this and we accept the regulator's ruling in complete. We will comply with the directive as soon as the timing and wording are finalised."
