The public service broadcaster was found to have committed a "major breach" of industry standards by omitting to mention that the narrator of a documentary about the Gaza conflict was the son of a Hamas official, according to regulatory body Ofcom.
An probe by Ofcom into Gaza: How to Survive a Warzone has found that the documentary was "materially misleading".
The head of the BBC had already issued an apology, stating there had been "a significant failing in relation to factual correctness".
The authority has directed the broadcaster to air a prime-time announcement about its conclusions.
"As this represents a major infringement of our code, we are instructing the BBC to broadcast a message of our conclusions against it on BBC2 at nine o'clock in the evening, with a schedule to be determined," the statement read.
'Possibility to Erode Trust'
The regulator's statement stated: "Our investigation concluded that the documentary's omission to reveal that the presenter's father held a role in the Hamas-controlled authority was substantially inaccurate.
"This implied that the public did not have critical information which may have been very significant to their assessment of the voice and the details he shared.
"Trust is at the core of the connection between a broadcaster and its public, particularly for a national broadcasting corporation such as the public broadcaster.
"This oversight had the risk to damage the exceptionally strong levels of trust that viewers would have placed in a BBC factual programme about the Israel-Gaza war."
The film was removed from the BBC's streaming service in February after the presenter's familial connections were revealed, and in the month of July an corporation's own inquiry concluded it breached the broadcaster's journalistic standards on truthfulness.
A corporation official commented: "The authority's determination is in agreement with the conclusions of the corporation's inquiry, that there was a major oversight in the film in relation to the broadcaster's journalistic policies on accuracy, which reflects clause 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we accept the regulator's ruling in its entirety. We will adhere to the penalty as soon as the timing and wording are finalised."
