The British broadcaster engaged in a "significant breach" of media regulations by omitting to mention that the voice of a documentary about Gaza was the offspring of a Hamas administrator, as ruled by British broadcasting authority Ofcom.
An inquiry by Ofcom into the programme Gaza: How to Survive a Warzone has concluded that the documentary was "materially misleading".
The BBC's director general had already issued an apology, stating there had been "a serious error in relation to truthfulness".
The authority has directed the broadcaster to air a evening announcement about its findings.
"Given this constitutes a major infringement of our regulations, we are instructing the broadcaster to transmit a message of our findings against it on BBC2 at 9pm, with a timing to be determined," the statement read.
'Possibility to Erode Confidence'
The authority's announcement stated: "Our probe concluded that the documentary's lack of disclosure that the voice's parent served in a role in the Hamas-run government was significantly deceptive.
"Consequently that the viewers did not have critical information which may have been extremely pertinent to their assessment of the presenter and the content he provided.
"Trust is at the heart of the relationship between a broadcaster and its audience, notably for a state-funded media outlet such as the BBC.
"This oversight had the potential to damage the significantly high degrees of credibility that audiences would have placed in a BBC factual programme about the Israel-Gaza war."
The documentary was withdrawn from the BBC's streaming service in the month of February after the presenter's family links emerged, and in this past July an broadcaster's internal assessment found it breached the organization's content policies on accuracy.
A BBC spokesperson said: "The Ofcom ruling is in line with the results of the corporation's inquiry, that there was a serious error in the film in relation to the corporation's content standards on truthfulness, which reflects regulation 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we accept Ofcom's decision in complete. We will follow the sanction as soon as the date and wording are confirmed."
