The British broadcaster engaged in a "major breach" of industry standards by failing to disclose that the voice of a film about the Gaza conflict was the son of a Hamas administrator, as ruled by British broadcasting authority Ofcom.
An probe by Ofcom into the documentary titled Gaza: How to Survive a Warzone has found that the film was "significantly deceptive".
The chief executive of the broadcaster had earlier expressed regret, noting there had been "a significant failing in relation to accuracy".
Ofcom has ordered the broadcaster to air a peak-time declaration about its conclusions.
"As this represents a major infringement of our code, we are directing the broadcaster to air a message of our determinations against it on the BBC's second channel at 21:00, with a timing to be determined," it said.
'Possibility to Damage Credibility'
The watchdog's report said: "Our probe determined that the programme's failure to disclose that the voice's male guardian occupied a post in the Hamas-controlled government was substantially inaccurate.
"It meant that the public did not have vital facts which may have been very significant to their evaluation of the narrator and the details he presented.
"Trust is at the heart of the connection between a television network and its public, notably for a public service broadcaster such as the public broadcaster.
"This error had the potential to undermine the significantly high degrees of credibility that the public would have placed in a factual film from the broadcaster about the conflict in Gaza."
The programme was pulled from iPlayer in February after the boy's familial connections emerged, and in this past July an broadcaster's internal assessment determined it infringed the corporation's editorial guidelines on accuracy.
A representative for the broadcaster stated: "The Ofcom ruling is in agreement with the findings of the internal assessment, that there was a significant failing in the programme in relation to the BBC's Editorial Guidelines on factual correctness, which aligns with Rule 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we agree with Ofcom's decision in full. We will comply with the sanction as soon as the schedule and wording are finalised."
