The British broadcaster committed a "major breach" of industry standards by failing to disclose that the narrator of a documentary about the Gaza situation was the child of a Hamas representative, according to regulatory body Ofcom.
An investigation by Ofcom into the programme Gaza: How to Survive a Warzone has found that the programme was "materially misleading".
The head of the BBC had previously apologised, saying there had been "a serious error in relation to factual correctness".
Ofcom has instructed the broadcaster to air a evening statement about its conclusions.
"Given this constitutes a major infringement of our regulations, we are instructing the corporation to broadcast a statement of our determinations against it on BBC2 at 21:00, with a schedule to be finalised," the statement read.
'Possibility to Damage Trust'
The watchdog's report said: "The inquiry we conducted concluded that the documentary's failure to disclose that the narrator's parent held a role in the Hamas-administered administration was substantially inaccurate.
"This implied that the viewers did not have vital facts which may have been very significant to their evaluation of the voice and the information he presented.
"Confidence is at the heart of the connection between a media organization and its audience, notably for a public service broadcaster such as the public broadcaster.
"This oversight had the potential to erode the very considerable levels of confidence that viewers would have put in a factual film from the broadcaster about the Israel-Gaza war."
The documentary was removed from iPlayer in last February after the boy's family links came to light, and in July an internal BBC review found it violated the corporation's journalistic standards on truthfulness.
A BBC spokesperson commented: "The Ofcom ruling is in accordance with the conclusions of the internal assessment, that there was a major oversight in the documentary in relation to the corporation's content standards on factual correctness, which reflects clause 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we comply with the authority's determination in complete. We will comply with the directive as soon as the schedule and wording are confirmed."
