The public service broadcaster was found to have committed a "serious breach" of broadcasting rules by failing to disclose that the narrator of a film about the Gaza conflict was the child of a Hamas official, according to UK media regulator Ofcom.
An inquiry by the media regulator into Gaza: How to Survive a Warzone has concluded that the documentary was "significantly deceptive".
The BBC's director general had earlier expressed regret, saying there had been "a serious error in relation to truthfulness".
The authority has ordered the broadcaster to air a evening declaration about its decisions.
"Since this amounts to a major infringement of our rules, we are directing the BBC to transmit a announcement of our findings against it on BBC2 at 21:00, with a timing to be confirmed," it said.
'Risk to Erode Trust'
The authority's announcement said: "Our investigation concluded that the documentary's failure to disclose that the presenter's father served in a role in the Hamas-controlled administration was substantially inaccurate.
"This implied that the audience did not have vital facts which may have been extremely pertinent to their judgment of the voice and the content he provided.
"Trust is at the heart of the relationship between a television network and its public, particularly for a state-funded media outlet such as the British Broadcasting Corporation.
"This failing had the potential to damage the significantly high levels of credibility that audiences would have placed in a factual film from the broadcaster about the Israel-Gaza war."
The documentary was pulled from the online platform in last February after the narrator's personal associations emerged, and in this past July an corporation's own inquiry concluded it breached the broadcaster's content policies on factual correctness.
A BBC spokesperson stated: "The regulator's decision is in agreement with the findings of the internal assessment, that there was a significant failing in the documentary in relation to the BBC's Editorial Guidelines on accuracy, which corresponds to regulation 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we agree with the regulator's ruling in its entirety. We will follow the sanction as soon as the timing and language are finalised."
