The BBC committed a "major breach" of industry standards by omitting to mention that the voice of a programme about the Gaza situation was the offspring of a Hamas official, according to British broadcasting authority Ofcom.
An inquiry by the media regulator into the documentary titled Gaza: How to Survive a Warzone has determined that the programme was "substantially inaccurate".
The BBC's director general had earlier expressed regret, noting there had been "a significant failing in relation to factual correctness".
Ofcom has ordered the broadcaster to air a prime-time statement about its decisions.
"As this represents a significant violation of our rules, we are instructing the BBC to air a message of our findings against it on BBC2 at 9pm, with a schedule to be finalised," the regulator stated.
'Possibility to Damage Credibility'
The authority's announcement said: "Our probe concluded that the documentary's omission to reveal that the voice's father occupied a post in the Hamas-run government was significantly deceptive.
"Consequently that the viewers did not have vital facts which may have been very significant to their evaluation of the presenter and the information he provided.
"Credibility is at the core of the connection between a media organization and its audience, particularly for a national broadcasting corporation such as the BBC.
"This error had the possibility to damage the very considerable levels of credibility that viewers would have invested in a documentary produced by the BBC about the Gaza conflict."
The documentary was removed from iPlayer in February after the narrator's family links were revealed, and in the month of July an broadcaster's internal assessment found it infringed the broadcaster's editorial guidelines on factual correctness.
A corporation official commented: "The authority's determination is in line with the conclusions of the corporation's inquiry, that there was a significant failing in the film in relation to the BBC's Editorial Guidelines on accuracy, which aligns with Rule 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we comply with the regulator's ruling in complete. We will adhere to the sanction as soon as the timing and wording are finalised."
