The BBC committed a "serious breach" of media regulations by not revealing that the voice of a documentary about the Gaza situation was the offspring of a Hamas administrator, as determined by regulatory body Ofcom.
An inquiry by the broadcasting watchdog into the documentary titled Gaza: How to Survive a Warzone has determined that the film was "significantly deceptive".
The BBC's director general had already issued an apology, noting there had been "a serious error in relation to truthfulness".
The regulator has instructed the BBC to air a evening announcement about its findings.
"As this represents a significant violation of our regulations, we are ordering the broadcaster to transmit a message of our conclusions against it on BBC Two at 9pm, with a timing to be confirmed," the statement read.
'Risk to Erode Confidence'
The authority's announcement said: "Our investigation found that the documentary's lack of disclosure that the voice's parent occupied a position in the Hamas-administered government was materially misleading.
"This implied that the audience did not have essential details which may have been extremely pertinent to their judgment of the narrator and the information he presented.
"Trust is at the core of the bond between a broadcaster and its viewers, particularly for a national broadcasting corporation such as the public broadcaster.
"This oversight had the possibility to damage the exceptionally strong amounts of trust that the public would have placed in a documentary produced by the BBC about the Israel-Gaza war."
The programme was withdrawn from the BBC's streaming service in the month of February after the presenter's personal associations emerged, and in the month of July an broadcaster's internal assessment determined it breached the corporation's content policies on truthfulness.
A BBC spokesperson commented: "The Ofcom ruling is in line with the conclusions of Peter Johnston's review, that there was a serious error in the programme in relation to the corporation's content standards on accuracy, which aligns with regulation 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we comply with the regulator's ruling in its entirety. We will follow the penalty as soon as the date and language are determined."
