The BBC engaged in a "serious breach" of media regulations by not revealing that the voice of a film about the Gaza situation was the offspring of a Hamas administrator, according to British broadcasting authority Ofcom.
An investigation by Ofcom into the programme Gaza: How to Survive a Warzone has determined that the documentary was "materially misleading".
The chief executive of the broadcaster had already issued an apology, noting there had been "a significant failing in relation to truthfulness".
Ofcom has directed the corporation to transmit a evening statement about its decisions.
"Since this amounts to a serious breach of our code, we are ordering the BBC to transmit a announcement of our determinations against it on BBC Two at nine o'clock in the evening, with a schedule to be finalised," it said.
'Possibility to Damage Trust'
The regulator's announcement declared: "Our investigation found that the programme's lack of disclosure that the presenter's father served in a role in the Hamas-controlled administration was materially misleading.
"This implied that the audience did not have essential details which may have been highly relevant to their evaluation of the voice and the content he provided.
"Confidence is at the center of the bond between a television network and its public, notably for a national broadcasting corporation such as the BBC.
"This error had the possibility to undermine the very considerable levels of credibility that the public would have placed in a BBC factual programme about the Gaza conflict."
The programme was removed from iPlayer in last February after the narrator's personal associations were revealed, and in July an broadcaster's internal assessment concluded it violated the organization's journalistic standards on truthfulness.
A representative for the broadcaster said: "The authority's determination is in agreement with the findings of Peter Johnston's review, that there was a major oversight in the programme in relation to the corporation's content standards on truthfulness, which corresponds to clause 2.2 of the regulator's media standards.
"We issued an apology for this and we accept Ofcom's decision in complete. We will adhere to the penalty as soon as the timing and language are confirmed."
