The BBC engaged in a "significant breach" of media regulations by not revealing that the narrator of a film about the Gaza conflict was the child of a Hamas official, as ruled by regulatory body Ofcom.
An inquiry by the media regulator into the programme Gaza: How to Survive a Warzone has determined that the programme was "materially misleading".
The head of the BBC had already issued an apology, stating there had been "a significant failing in relation to truthfulness".
The regulator has directed the corporation to broadcast a evening announcement about its findings.
"As this represents a significant violation of our rules, we are instructing the BBC to broadcast a message of our conclusions against it on the BBC's second channel at nine o'clock in the evening, with a date to be confirmed," it said.
'Potential to Undermine Confidence'
The watchdog's report said: "Our probe concluded that the documentary's lack of disclosure that the presenter's father occupied a role in the Hamas-controlled administration was significantly deceptive.
"It meant that the audience did not have vital facts which may have been extremely pertinent to their judgment of the voice and the details he presented.
"Confidence is at the heart of the bond between a broadcaster and its audience, especially for a national broadcasting corporation such as the BBC.
"This oversight had the risk to damage the very considerable amounts of trust that viewers would have put in a factual film from the broadcaster about the conflict in Gaza."
The programme was removed from iPlayer in last February after the narrator's familial connections came to light, and in July an broadcaster's internal assessment concluded it violated the corporation's editorial guidelines on factual correctness.
A corporation official commented: "The Ofcom ruling is in accordance with the conclusions of the internal assessment, that there was a major oversight in the programme in relation to the BBC's Editorial Guidelines on factual correctness, which reflects Rule 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 adhere to the directive as soon as the schedule and wording are finalised."
