The BBC engaged in a "significant breach" of media regulations by not revealing that the presenter of a film about Gaza was the child of a Hamas representative, as determined by British broadcasting authority Ofcom.
An inquiry by the broadcasting watchdog into Gaza: How to Survive a Warzone has determined that the programme was "substantially inaccurate".
The head of the BBC had previously apologised, saying there had been "a serious error in relation to factual correctness".
The authority has ordered the corporation to air a peak-time statement about its findings.
"As this represents a serious breach of our rules, we are ordering the corporation to broadcast a announcement of our determinations against it on BBC2 at 21:00, with a schedule to be determined," it said.
'Potential to Undermine Credibility'
The watchdog's announcement declared: "Our probe found that the film's omission to reveal that the voice's father served in a role in the Hamas-administered authority was significantly deceptive.
"Consequently that the audience did not have critical information which may have been extremely pertinent to their judgment of the presenter and the information he shared.
"Trust is at the heart of the bond between a broadcaster and its public, especially for a public service broadcaster such as the British Broadcasting Corporation.
"This failing had the risk to erode the very considerable degrees of trust that audiences would have invested in a documentary produced by the BBC about the Gaza conflict."
The documentary was withdrawn from the BBC's streaming service in the month of February after the narrator's personal associations came to light, and in the month of July an internal BBC review concluded it breached the broadcaster's journalistic standards on factual correctness.
A corporation official commented: "The regulator's decision is in agreement with the findings of Peter Johnston's review, that there was a serious error in the programme in relation to the corporation's content standards on factual correctness, which corresponds to clause 2.2 of the regulator's media standards.
"We have apologised for this and we comply with the authority's determination in its entirety. We will follow the penalty as soon as the timing and wording are determined."
