The public service broadcaster engaged in a "serious breach" of industry standards by not revealing that the voice of a documentary about the Gaza situation was the son of a Hamas representative, according to regulatory body Ofcom.
An probe by the media regulator into Gaza: How to Survive a Warzone has determined that the documentary was "substantially inaccurate".
The chief executive of the broadcaster had already issued an apology, stating there had been "a serious error in relation to accuracy".
The regulator has ordered the corporation to transmit a peak-time announcement about its decisions.
"Since this amounts to a major infringement of our regulations, we are instructing the corporation to broadcast a message of our conclusions against it on BBC2 at nine o'clock in the evening, with a timing to be determined," the statement read.
'Risk to Erode Trust'
The authority's statement stated: "The inquiry we conducted concluded that the documentary's lack of disclosure that the narrator's male guardian held a post in the Hamas-administered authority was significantly deceptive.
"Consequently that the audience did not have essential details which may have been highly relevant to their assessment of the narrator and the information he provided.
"Trust is at the heart of the connection between a media organization and its viewers, especially for a state-funded media outlet such as the British Broadcasting Corporation.
"This oversight had the risk to erode the significantly high levels of trust that the public would have put in a documentary produced by the BBC about the conflict in Gaza."
The documentary was removed from the online platform in February after the narrator's family links were revealed, and in the month of July an corporation's own inquiry concluded it violated the broadcaster's content policies on truthfulness.
A representative for the broadcaster commented: "The regulator's decision is in line with the results of the corporation's inquiry, that there was a serious error in the documentary in relation to the broadcaster's journalistic policies on truthfulness, which reflects clause 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we accept Ofcom's decision in its entirety. We will follow the penalty as soon as the timing and wording are determined."