The public service broadcaster was found to have committed a "major breach" of industry standards by failing to disclose that the voice of a documentary about Gaza was the son of a Hamas administrator, according to UK media regulator Ofcom.
An probe by the broadcasting watchdog into the programme Gaza: How to Survive a Warzone has determined that the programme was "materially misleading".
The BBC's director general had earlier expressed regret, stating there had been "a significant failing in relation to truthfulness".
The authority has instructed the broadcaster to transmit a peak-time announcement about its conclusions.
"As this represents a serious breach of our rules, we are instructing the corporation to broadcast a statement of our findings against it on BBC2 at 21:00, with a date to be finalised," the statement read.
'Potential to Undermine Trust'
The watchdog's report said: "Our probe found that the documentary's omission to reveal that the presenter's male guardian occupied a post in the Hamas-run authority was materially misleading.
"Consequently that the viewers did not have essential details which may have been very significant to their judgment of the presenter and the content he presented.
"Credibility is at the center of the bond between a television network and its viewers, notably for a state-funded media outlet such as the public broadcaster.
"This oversight had the potential to damage the very considerable levels of trust that viewers would have placed in a documentary produced by the BBC about the conflict in Gaza."
The film was withdrawn from iPlayer in the month of February after the narrator's personal associations emerged, and in July an corporation's own inquiry found it breached the broadcaster's editorial guidelines on accuracy.
A corporation official commented: "The regulator's decision is in accordance with the findings of the internal assessment, that there was a serious error in the documentary in relation to the broadcaster's journalistic policies on truthfulness, which reflects Rule 2.2 of the regulator's media standards.
"We expressed regret for this and we agree with the regulator's ruling in complete. We will comply with the penalty as soon as the schedule and language are finalised."
