The British broadcaster engaged in a "significant breach" of broadcasting rules by omitting to mention that the presenter of a documentary about the Gaza situation was the offspring of a Hamas administrator, as ruled by British broadcasting authority Ofcom.
An probe by Ofcom into Gaza: How to Survive a Warzone has determined that the film was "substantially inaccurate".
The chief executive of the broadcaster had previously apologised, noting there had been "a significant failing in relation to truthfulness".
Ofcom has ordered the BBC to air a evening declaration about its findings.
"Given this constitutes a serious breach of our regulations, we are directing the broadcaster to transmit a announcement of our findings against it on BBC Two at 9pm, with a timing to be determined," it said.
'Possibility to Undermine Confidence'
The watchdog's report stated: "Our investigation concluded that the documentary's omission to reveal that the presenter's father held a post in the Hamas-administered authority was materially misleading.
"Consequently that the audience did not have critical information which may have been extremely pertinent to their evaluation of the narrator and the content he provided.
"Credibility is at the center of the bond between a media organization and its viewers, particularly for a national broadcasting corporation such as the British Broadcasting Corporation.
"This failing had the risk to damage the very considerable amounts of trust that the public would have invested in a documentary produced by the BBC about the conflict in Gaza."
The programme was removed from iPlayer in last February after the narrator's personal associations emerged, and in July an corporation's own inquiry found it infringed the corporation's journalistic standards on accuracy.
A BBC spokesperson said: "The regulator's decision is in accordance with the results of the internal assessment, that there was a serious error in the documentary in relation to the broadcaster's journalistic policies on accuracy, which corresponds to regulation 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we agree with Ofcom's decision in complete. We will follow the penalty as soon as the schedule and wording are determined."
