The BBC committed a "significant breach" of media regulations by omitting to mention that the presenter of a documentary about the Gaza conflict was the offspring of a Hamas administrator, according to regulatory body Ofcom.
An probe by the broadcasting watchdog into the programme Gaza: How to Survive a Warzone has found that the documentary was "significantly deceptive".
The head of the BBC had already issued an apology, saying there had been "a serious error in relation to accuracy".
The regulator has instructed the BBC to air a prime-time announcement about its findings.
"Given this constitutes a significant violation of our regulations, we are directing the corporation to broadcast a announcement of our findings against it on BBC2 at 21:00, with a schedule to be finalised," the regulator stated.
'Risk to Damage Confidence'
The authority's statement said: "Our investigation determined that the documentary's failure to disclose that the narrator's parent held a post in the Hamas-run administration was materially misleading.
"It meant that the viewers did not have essential details which may have been extremely pertinent to their evaluation of the presenter and the details he provided.
"Credibility is at the center of the relationship between a media organization and its public, notably for a public service broadcaster such as the BBC.
"This failing had the possibility to undermine the very considerable levels of trust that viewers would have put in a documentary produced by the BBC about the Israel-Gaza war."
The documentary was withdrawn from iPlayer in February after the boy's familial connections were revealed, and in July an corporation's own inquiry concluded it breached the broadcaster's journalistic standards on factual correctness.
A corporation official commented: "The authority's determination is in line with the conclusions of Peter Johnston's review, that there was a major oversight in the programme in relation to the BBC's Editorial Guidelines on factual correctness, which reflects clause 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 follow the sanction as soon as the schedule and wording are finalised."
