The public service broadcaster engaged in a "serious breach" of industry standards by not revealing that the voice of a programme about the Gaza situation was the son of a Hamas administrator, according to British broadcasting authority Ofcom.
An probe by the media regulator into Gaza: How to Survive a Warzone has determined that the documentary was "substantially inaccurate".
The head of the BBC had earlier expressed regret, saying there had been "a serious error in relation to accuracy".
The authority has instructed the corporation to air a peak-time statement about its findings.
"Given this constitutes a significant violation of our code, we are directing the BBC to transmit a announcement of our conclusions against it on BBC Two at 21:00, with a date to be confirmed," the statement read.
'Possibility to Undermine Trust'
The authority's report stated: "Our investigation found that the film's failure to disclose that the voice's male guardian served in a post in the Hamas-run administration was materially misleading.
"Consequently that the audience did not have vital facts which may have been highly relevant to their assessment of the narrator and the information he shared.
"Confidence is at the heart of the connection between a media organization and its viewers, notably for a public service broadcaster such as the BBC.
"This oversight had the possibility to damage the exceptionally strong amounts of credibility that viewers would have placed in a documentary produced by the BBC about the Gaza conflict."
The documentary was pulled from the online platform in February after the presenter's family links came to light, and in the month of July an corporation's own inquiry determined it infringed the broadcaster's editorial guidelines on factual correctness.
A representative for the broadcaster said: "The regulator's decision is in line with the conclusions of the corporation's inquiry, that there was a significant failing in the film in relation to the corporation's content standards on factual correctness, which reflects clause 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we accept the regulator's ruling in its entirety. We will adhere to the penalty as soon as the timing and wording are determined."
