The British broadcaster committed a "major breach" of broadcasting rules by not revealing that the presenter of a programme about the Gaza conflict was the son of a Hamas representative, according to regulatory body Ofcom.
An investigation by the broadcasting watchdog into the programme Gaza: How to Survive a Warzone has found that the film was "materially misleading".
The BBC's director general had already issued an apology, noting there had been "a significant failing in relation to factual correctness".
The authority has instructed the BBC to transmit a prime-time announcement about its findings.
"As this represents a major infringement of our regulations, we are instructing the BBC to broadcast a announcement of our determinations against it on BBC2 at 9pm, with a schedule to be finalised," the statement read.
'Possibility to Undermine Credibility'
The authority's report said: "The inquiry we conducted concluded that the programme's lack of disclosure that the voice's father served in a role in the Hamas-run administration was materially misleading.
"It meant that the viewers did not have vital facts which may have been highly relevant to their assessment of the presenter and the information he shared.
"Credibility is at the core of the connection between a media organization and its viewers, particularly for a state-funded media outlet such as the British Broadcasting Corporation.
"This oversight had the risk to damage the significantly high degrees of trust that viewers would have invested in a factual film from the broadcaster about the Gaza conflict."
The programme was pulled from iPlayer in February after the boy's personal associations came to light, and in July an broadcaster's internal assessment found it breached the corporation's content policies on factual correctness.
A representative for the broadcaster commented: "The authority's determination is in accordance with the conclusions of the corporation's inquiry, that there was a significant failing in the documentary in relation to the BBC's Editorial Guidelines on factual correctness, which corresponds to clause 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we agree with the regulator's ruling in its entirety. We will adhere to the penalty as soon as the timing and wording are finalised."
