The BBC was found to have committed a "major breach" of media regulations by not revealing that the voice of a programme about Gaza was the son of a Hamas representative, as ruled by regulatory body Ofcom.
An investigation by Ofcom into the programme Gaza: How to Survive a Warzone has found that the programme was "materially misleading".
The chief executive of the broadcaster had previously apologised, stating there had been "a serious error in relation to accuracy".
The authority has directed the broadcaster to air a evening announcement about its findings.
"Given this constitutes a serious breach of our regulations, we are ordering the BBC to transmit a announcement of our conclusions against it on BBC Two at 9pm, with a timing to be finalised," the statement read.
'Potential to Damage Trust'
The regulator's report said: "Our probe concluded that the programme's failure to disclose that the narrator's parent held a post in the Hamas-administered government was significantly deceptive.
"This implied that the audience did not have critical information which may have been highly relevant to their evaluation of the voice and the content he shared.
"Trust is at the center of the connection between a media organization and its public, notably for a national broadcasting corporation such as the British Broadcasting Corporation.
"This oversight had the possibility to undermine the very considerable amounts of credibility that viewers would have invested in a documentary produced by the BBC about the conflict in Gaza."
The programme was withdrawn from iPlayer in February after the narrator's familial connections emerged, and in the month of July an broadcaster's internal assessment found it breached the corporation's journalistic standards on truthfulness.
A BBC spokesperson commented: "The Ofcom ruling is in line with the conclusions of the corporation's inquiry, that there was a significant failing in the documentary in relation to the corporation's content standards on accuracy, which corresponds to clause 2.2 of the regulator's media standards.
"We issued an apology for this and we agree with Ofcom's decision in complete. We will adhere to the sanction as soon as the schedule and language are finalised."
