The public service broadcaster engaged in a "serious breach" of media regulations by not revealing that the presenter of a programme about Gaza was the child of a Hamas official, according to British broadcasting authority Ofcom.
An investigation by the broadcasting watchdog into Gaza: How to Survive a Warzone has concluded that the documentary was "significantly deceptive".
The BBC's director general had previously apologised, noting there had been "a serious error in relation to truthfulness".
The authority has instructed the BBC to air a peak-time declaration about its findings.
"Given this constitutes a serious breach of our regulations, we are instructing the broadcaster to broadcast a statement of our findings against it on the BBC's second channel at 9pm, with a date to be determined," it said.
'Risk to Undermine Trust'
The watchdog's announcement said: "Our probe found that the documentary's failure to disclose that the narrator's male guardian held a role in the Hamas-controlled administration was significantly deceptive.
"It meant that the public did not have essential details which may have been extremely pertinent to their judgment of the presenter and the content he provided.
"Credibility is at the core of the relationship between a broadcaster and its viewers, particularly for a state-funded media outlet such as the public broadcaster.
"This error had the risk to damage the significantly high amounts of confidence that viewers would have invested in a factual film from the broadcaster about the Israel-Gaza war."
The documentary was removed from the online platform in the month of February after the presenter's family links were revealed, and in the month of July an internal BBC review found it violated the broadcaster's journalistic standards on factual correctness.
A representative for the broadcaster stated: "The regulator's decision is in line with the results of Peter Johnston's review, that there was a significant failing in the programme in relation to the corporation's content standards on truthfulness, which aligns with regulation 2.2 of the authority's broadcasting regulations.
"We have apologised for this and we agree with Ofcom's decision in its entirety. We will adhere to the penalty as soon as the timing and language are finalised."
