The British broadcaster was found to have committed a "serious breach" of broadcasting rules by not revealing that the narrator of a documentary about Gaza was the offspring of a Hamas administrator, as determined by UK media regulator Ofcom.
An inquiry by the broadcasting watchdog into Gaza: How to Survive a Warzone has found that the programme was "materially misleading".
The BBC's director general had earlier expressed regret, saying there had been "a serious error in relation to truthfulness".
Ofcom has directed the corporation to transmit a peak-time announcement about its conclusions.
"Since this amounts to a major infringement of our rules, we are directing the corporation to transmit a announcement of our findings against it on BBC2 at 21:00, with a date to be finalised," the regulator stated.
'Potential to Erode Credibility'
The watchdog's report declared: "Our probe determined that the documentary's failure to disclose that the voice's parent served in a role in the Hamas-controlled authority was significantly deceptive.
"Consequently that the viewers did not have critical information which may have been very significant to their judgment of the narrator and the information he shared.
"Credibility is at the core of the connection between a broadcaster and its public, especially for a national broadcasting corporation such as the public broadcaster.
"This oversight had the possibility to damage the significantly high levels of credibility that the public would have invested in a documentary produced by the BBC about the conflict in Gaza."
The documentary was pulled from iPlayer in February after the presenter's family links were revealed, and in July an internal BBC review found it violated the broadcaster's content policies on factual correctness.
A BBC spokesperson said: "The regulator's decision is in accordance with the findings of the internal assessment, that there was a serious error in the film in relation to the broadcaster's journalistic policies on truthfulness, which aligns with clause 2.2 of the regulator's media standards.
"We expressed regret for this and we agree with the authority's determination in its entirety. We will follow the penalty as soon as the schedule and language are determined."
