The BBC engaged in a "significant breach" of media regulations by not revealing that the presenter of a programme about the Gaza situation was the offspring of a Hamas official, according to British broadcasting authority Ofcom.
An investigation by Ofcom into the programme Gaza: How to Survive a Warzone has found that the programme was "significantly deceptive".
The chief executive of the broadcaster had earlier expressed regret, saying there had been "a major oversight in relation to truthfulness".
The regulator has directed the corporation to broadcast a evening statement about its findings.
"Since this amounts to a significant violation of our rules, we are instructing the corporation to transmit a statement of our conclusions against it on the BBC's second channel at nine o'clock in the evening, with a schedule to be determined," it said.
'Risk to Damage Credibility'
The authority's report said: "Our investigation determined that the programme's lack of disclosure that the voice's parent held a position in the Hamas-run authority was substantially inaccurate.
"It meant that the audience did not have critical information which may have been very significant to their assessment of the narrator and the content he provided.
"Credibility is at the core of the relationship between a broadcaster and its public, notably for a public service broadcaster such as the British Broadcasting Corporation.
"This oversight had the possibility to undermine the significantly high degrees of trust that the public would have invested in a BBC factual programme about the conflict in Gaza."
The documentary was pulled from iPlayer in the month of February after the narrator's personal associations emerged, and in this past July an corporation's own inquiry concluded it infringed the broadcaster's editorial guidelines on truthfulness.
A representative for the broadcaster said: "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 BBC's Editorial Guidelines on accuracy, which corresponds to clause 2.2 of the regulator's media standards.
"We expressed regret for this and we comply with the regulator's ruling in complete. We will follow the penalty as soon as the schedule and wording are confirmed."
