The British broadcaster was found to have committed a "major breach" of industry standards by omitting to mention that the narrator of a programme about the Gaza situation was the child of a Hamas official, as ruled by regulatory body Ofcom.
An probe by the broadcasting watchdog into Gaza: How to Survive a Warzone has concluded that the programme was "substantially inaccurate".
The BBC's director general had earlier expressed regret, saying there had been "a major oversight in relation to factual correctness".
The authority has instructed the BBC to transmit a evening declaration about its findings.
"Given this constitutes a major infringement of our code, we are directing the broadcaster to transmit a announcement of our conclusions against it on BBC Two at 21:00, with a date to be confirmed," the statement read.
'Potential to Damage Trust'
The authority's announcement declared: "The inquiry we conducted determined that the documentary's omission to reveal that the narrator's father served in a role in the Hamas-controlled administration was substantially inaccurate.
"This implied that the public did not have essential details which may have been extremely pertinent to their assessment of the voice and the information he presented.
"Credibility is at the center of the connection between a television network and its audience, especially for a state-funded media outlet such as the BBC.
"This error had the possibility to erode the significantly high levels of confidence that viewers would have placed in a documentary produced by the BBC about the conflict in Gaza."
The documentary was removed from iPlayer in last February after the presenter's familial connections came to light, and in this past July an internal BBC review found it infringed the organization's journalistic standards on factual correctness.
A corporation official stated: "The regulator's decision is in accordance with the conclusions of the corporation's inquiry, that there was a significant failing in the documentary in relation to the BBC's Editorial Guidelines on truthfulness, which aligns with Rule 2.2 of the authority's broadcasting regulations.
"We have apologised for this and we agree with the authority's determination in complete. We will follow the penalty as soon as the schedule and wording are confirmed."
