The BBC engaged in a "serious breach" of broadcasting rules by omitting to mention that the voice of a documentary about Gaza was the son of a Hamas administrator, as determined by regulatory body Ofcom.
An investigation by the media regulator into the programme Gaza: How to Survive a Warzone has determined that the programme was "materially misleading".
The chief executive of the broadcaster had previously apologised, stating there had been "a major oversight in relation to accuracy".
The authority has ordered the BBC to transmit a evening declaration about its conclusions.
"As this represents a major infringement of our code, we are ordering the broadcaster to broadcast a statement of our conclusions against it on BBC2 at 21:00, with a schedule to be determined," it said.
'Possibility to Erode Trust'
The watchdog's announcement stated: "Our investigation concluded that the documentary's failure to disclose that the voice's parent served in a role in the Hamas-administered authority was substantially inaccurate.
"This implied that the audience did not have vital facts which may have been extremely pertinent to their evaluation of the narrator and the content he presented.
"Trust is at the core of the connection between a television network and its audience, especially for a national broadcasting corporation such as the BBC.
"This oversight had the risk to undermine the significantly high levels of credibility that viewers would have put in a BBC factual programme about the Israel-Gaza war."
The programme was withdrawn from iPlayer in the month of February after the narrator's personal associations emerged, and in this past July an broadcaster's internal assessment determined it infringed the organization's content policies on factual correctness.
A BBC spokesperson commented: "The regulator's decision is in line with the results of Peter Johnston's review, that there was a significant failing in the documentary in relation to the corporation's content standards on factual correctness, which reflects clause 2.2 of the regulator's media standards.
"We issued an apology for this and we agree with the regulator's ruling in its entirety. We will follow the sanction as soon as the date and wording are confirmed."
