The British broadcaster engaged in a "major breach" of industry standards by failing to disclose that the presenter of a film about the Gaza conflict was the son of a Hamas administrator, according to regulatory body Ofcom.
An probe by the media regulator into the documentary titled Gaza: How to Survive a Warzone has found that the programme was "significantly deceptive".
The BBC's director general had earlier expressed regret, noting there had been "a serious error in relation to factual correctness".
Ofcom has ordered the corporation to air a evening announcement about its decisions.
"Since this amounts to a serious breach of our regulations, we are ordering the BBC to air a message of our determinations against it on BBC2 at 21:00, with a timing to be determined," it said.
'Potential to Damage Trust'
The watchdog's statement stated: "Our investigation found that the programme's omission to reveal that the voice's parent occupied a role in the Hamas-run administration was significantly deceptive.
"This implied that the public did not have vital facts which may have been extremely pertinent to their judgment of the presenter and the information he provided.
"Confidence is at the center of the bond between a media organization and its audience, particularly for a state-funded media outlet such as the British Broadcasting Corporation.
"This failing had the risk to erode the significantly high degrees of confidence that viewers would have invested in a factual film from the broadcaster about the Gaza conflict."
The programme was pulled from the online platform in February after the boy's family links came to light, and in this past July an internal BBC review determined it infringed the organization's journalistic standards on accuracy.
A representative for the broadcaster said: "The authority's determination is in accordance with the conclusions of the corporation's inquiry, that there was a serious error in the film in relation to the corporation's content standards on factual correctness, which reflects Rule 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we agree with the regulator's ruling in its entirety. We will comply with the sanction as soon as the date and language are determined."