The BBC engaged in a "serious breach" of industry standards by not revealing that the presenter of a programme about the Gaza conflict was the son of a Hamas administrator, as ruled by UK media regulator Ofcom.
An investigation by Ofcom into Gaza: How to Survive a Warzone has found that the film was "substantially inaccurate".
The chief executive of the broadcaster had earlier expressed regret, stating there had been "a significant failing in relation to truthfulness".
The authority has ordered the BBC to air a peak-time declaration about its conclusions.
"Since this amounts to a serious breach of our rules, we are instructing the broadcaster to broadcast a announcement of our determinations against it on the BBC's second channel at 21:00, with a timing to be finalised," the statement read.
'Possibility to Erode Confidence'
The authority's announcement said: "Our investigation concluded that the documentary's lack of disclosure that the narrator's father occupied a role in the Hamas-controlled administration was substantially inaccurate.
"This implied that the audience did not have vital facts which may have been extremely pertinent to their judgment of the voice and the content he presented.
"Trust is at the heart of the relationship between a media organization and its public, especially for a public service broadcaster such as the public broadcaster.
"This oversight had the possibility to damage the significantly high degrees of confidence that viewers would have invested in a BBC factual programme about the Israel-Gaza war."
The film was withdrawn from iPlayer in the month of February after the boy's familial connections came to light, and in July an broadcaster's internal assessment determined it breached the corporation's content policies on truthfulness.
A corporation official commented: "The regulator's decision is in line with the conclusions of the corporation's inquiry, that there was a serious error in the programme in relation to the corporation's content standards on factual correctness, which corresponds to clause 2.2 of the authority's broadcasting regulations.
"We have apologised for this and we comply with Ofcom's decision in its entirety. We will adhere to the directive as soon as the schedule and language are confirmed."
