The BBC was found to have committed a "major breach" of media regulations by omitting to mention that the voice of a programme about the Gaza situation was the child of a Hamas representative, according to regulatory body Ofcom.
An probe by the media regulator into the programme Gaza: How to Survive a Warzone has found that the documentary was "materially misleading".
The head of the BBC had previously apologised, saying there had been "a serious error in relation to truthfulness".
The regulator has ordered the broadcaster to transmit a evening statement about its findings.
"Since this amounts to a serious breach of our rules, we are instructing the broadcaster to broadcast a statement of our findings against it on BBC Two at 21:00, with a schedule to be determined," it said.
'Risk to Undermine Confidence'
The watchdog's statement stated: "Our probe found that the film's omission to reveal that the voice's male guardian served in a post in the Hamas-administered government was significantly deceptive.
"This implied that the public did not have critical information which may have been very significant to their assessment of the voice and the information he shared.
"Credibility is at the core of the relationship between a television network and its audience, notably for a state-funded media outlet such as the BBC.
"This oversight had the possibility to undermine the very considerable amounts of credibility that audiences would have placed in a documentary produced by the BBC about the Gaza conflict."
The programme was withdrawn from iPlayer in the month of February after the presenter's family links emerged, and in this past July an internal BBC review determined it breached the corporation's journalistic standards on factual correctness.
A BBC spokesperson commented: "The authority's determination is in agreement with the conclusions of the corporation's inquiry, that there was a serious error in the documentary in relation to the BBC's Editorial Guidelines on factual correctness, which reflects regulation 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we comply with Ofcom's decision in full. We will follow the sanction as soon as the timing and wording are confirmed."
