The British broadcaster committed a "serious breach" of industry standards by omitting to mention that the voice of a documentary about the Gaza situation was the offspring of a Hamas representative, according to regulatory body Ofcom.
An investigation by Ofcom into Gaza: How to Survive a Warzone has found that the documentary was "substantially inaccurate".
The BBC's director general had already issued an apology, stating there had been "a major oversight in relation to accuracy".
The regulator has ordered the corporation to air a peak-time declaration about its decisions.
"Given this constitutes a serious breach of our code, we are ordering the corporation to air a message of our findings against it on BBC2 at nine o'clock in the evening, with a schedule to be confirmed," the regulator stated.
'Risk to Erode Trust'
The regulator's statement stated: "The inquiry we conducted found that the documentary's failure to disclose that the narrator's parent served in a post in the Hamas-administered government was materially misleading.
"Consequently that the public did not have critical information which may have been extremely pertinent to their judgment of the narrator and the information he shared.
"Confidence is at the core of the bond between a television network and its viewers, particularly for a public service broadcaster such as the public broadcaster.
"This oversight had the risk to erode the exceptionally strong degrees of trust that the public would have invested in a factual film from the broadcaster about the Israel-Gaza war."
The documentary was pulled from the BBC's streaming service in last February after the presenter's family links were revealed, and in the month of July an internal BBC review found it breached the broadcaster's journalistic standards on truthfulness.
A representative for the broadcaster said: "The Ofcom ruling is in agreement with the findings of the corporation's inquiry, that there was a significant failing in the programme in relation to the corporation's content standards on accuracy, which reflects regulation 2.2 of the authority's broadcasting regulations.
"We have apologised for this and we agree with the regulator's ruling in its entirety. We will follow the penalty as soon as the date and language are finalised."
