The BBC committed a "serious breach" of broadcasting rules by omitting to mention that the narrator of a documentary about the Gaza situation was the child of a Hamas representative, as ruled by British broadcasting authority Ofcom.
An probe by Ofcom into Gaza: How to Survive a Warzone has determined that the programme was "significantly deceptive".
The BBC's director general had earlier expressed regret, saying there had been "a major oversight in relation to truthfulness".
The regulator has ordered the BBC to broadcast a prime-time announcement about its decisions.
"Given this constitutes a significant violation of our regulations, we are ordering the BBC to broadcast a announcement of our determinations against it on the BBC's second channel at 21:00, with a schedule to be finalised," it said.
'Risk to Erode Credibility'
The authority's statement stated: "Our probe determined that the programme's lack of disclosure that the presenter's male guardian held a role in the Hamas-controlled government was significantly deceptive.
"This implied that the public did not have vital facts which may have been extremely pertinent to their evaluation of the presenter and the details he presented.
"Trust is at the center of the bond between a media organization and its viewers, notably for a state-funded media outlet such as the British Broadcasting Corporation.
"This error had the potential to damage the significantly high levels of credibility that viewers would have placed in a documentary produced by the BBC about the Israel-Gaza war."
The film was withdrawn from iPlayer in the month of February after the narrator's family links emerged, and in July an internal BBC review concluded it infringed the organization's content policies on truthfulness.
A corporation official stated: "The regulator's decision is in accordance with the findings of the corporation's inquiry, that there was a major oversight in the documentary in relation to the broadcaster's journalistic policies on truthfulness, which aligns with clause 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we comply with the authority's determination in full. We will comply with the penalty as soon as the timing and wording are determined."
