The public service broadcaster was found to have committed a "significant breach" of industry standards by not revealing that the presenter of a programme about the Gaza situation was the offspring of a Hamas official, as ruled by UK media regulator Ofcom.
An probe by Ofcom into the programme Gaza: How to Survive a Warzone has concluded that the documentary was "substantially inaccurate".
The BBC's director general had earlier expressed regret, saying there had been "a significant failing in relation to truthfulness".
The authority has ordered the BBC to transmit a evening statement about its conclusions.
"As this represents a serious breach of our rules, we are ordering the broadcaster to broadcast a announcement of our conclusions against it on BBC Two at 21:00, with a schedule to be confirmed," the regulator stated.
'Potential to Damage Trust'
The regulator's statement stated: "Our investigation concluded that the documentary's omission to reveal that the presenter's parent occupied a position in the Hamas-controlled administration was substantially inaccurate.
"It meant that the audience did not have critical information which may have been extremely pertinent to their assessment of the voice and the details he shared.
"Confidence is at the heart of the connection between a television network and its viewers, notably for a public service broadcaster such as the public broadcaster.
"This error had the potential to erode the very considerable degrees of trust that the public would have put in a factual film from the broadcaster about the conflict in Gaza."
The documentary was withdrawn from iPlayer in February after the narrator's familial connections came to light, and in July an internal BBC review concluded it breached the corporation's journalistic standards on truthfulness.
A BBC spokesperson stated: "The regulator's decision is in agreement with the conclusions of Peter Johnston's review, that there was a major oversight in the documentary in relation to the broadcaster's journalistic policies on truthfulness, which reflects clause 2.2 of the regulator's media standards.
"We have apologised for this and we accept Ofcom's decision in complete. We will adhere to the sanction as soon as the timing and wording are finalised."
