The public service broadcaster was found to have committed a "major breach" of broadcasting rules by failing to disclose that the voice of a documentary about the Gaza situation was the son of a Hamas representative, according to UK media regulator Ofcom.
An investigation by Ofcom into Gaza: How to Survive a Warzone has found that the film was "substantially inaccurate".
The BBC's director general had already issued an apology, stating there had been "a major oversight in relation to accuracy".
The authority has directed the BBC to air a evening announcement about its decisions.
"As this represents a significant violation of our code, we are directing the corporation to transmit a message of our findings against it on BBC Two at 9pm, with a timing to be finalised," the statement read.
'Risk to Erode Credibility'
The regulator's statement said: "Our investigation concluded that the documentary's omission to reveal that the presenter's male guardian held a position in the Hamas-administered government was significantly deceptive.
"Consequently that the audience did not have critical information which may have been very significant to their assessment of the presenter and the content he shared.
"Confidence is at the core of the bond between a broadcaster and its audience, notably for a national broadcasting corporation such as the public broadcaster.
"This error had the risk to damage the exceptionally strong levels of confidence that viewers would have placed in a factual film from the broadcaster about the Gaza conflict."
The documentary was pulled from iPlayer in last February after the narrator's family links were revealed, and in July an corporation's own inquiry concluded it violated the organization's editorial guidelines on factual correctness.
A representative for the broadcaster commented: "The regulator's decision is in agreement with the findings of Peter Johnston's review, that there was a major oversight in the programme in relation to the BBC's Editorial Guidelines on truthfulness, which reflects clause 2.2 of the authority's broadcasting regulations.
"We have apologised for this and we comply with the authority's determination in complete. We will follow the sanction as soon as the schedule and wording are confirmed."
