The British broadcaster engaged in a "significant breach" of industry standards by not revealing that the narrator of a programme about the Gaza situation was the offspring of a Hamas official, as determined by regulatory body Ofcom.
An investigation 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 earlier expressed regret, noting there had been "a significant failing in relation to accuracy".
Ofcom has ordered the broadcaster to air a prime-time declaration about its conclusions.
"Since this amounts to a significant violation of our code, we are ordering the BBC to transmit a statement of our conclusions against it on BBC Two at 21:00, with a schedule to be determined," the statement read.
'Risk to Erode Trust'
The regulator's statement stated: "Our probe concluded that the documentary's omission to reveal that the presenter's male guardian occupied a role in the Hamas-run government was materially misleading.
"It meant that the public did not have critical information which may have been highly relevant to their assessment of the presenter and the details he presented.
"Credibility is at the core of the relationship between a media organization and its public, notably for a state-funded media outlet such as the BBC.
"This oversight had the risk to undermine the exceptionally strong degrees of trust that viewers would have invested in a BBC factual programme about the Gaza conflict."
The programme was pulled from the BBC's streaming service in the month of February after the presenter's family links came to light, and in the month of July an corporation's own inquiry found it infringed the organization's journalistic standards on factual correctness.
A BBC spokesperson said: "The regulator's decision is in line with the results of the corporation's inquiry, that there was a significant failing in the documentary in relation to the BBC's Editorial Guidelines on accuracy, which aligns with clause 2.2 of the regulator's media standards.
"We have apologised for this and we agree with Ofcom's decision in its entirety. We will adhere to the sanction as soon as the date and wording are determined."
