The BBC was found to have committed a "serious breach" of broadcasting rules by omitting to mention that the narrator of a documentary about Gaza was the son of a Hamas administrator, as determined by regulatory body Ofcom.
An investigation by the media regulator into the programme Gaza: How to Survive a Warzone has found that the documentary was "materially misleading".
The BBC's director general had already issued an apology, stating there had been "a major oversight in relation to truthfulness".
The authority has directed the corporation to broadcast a peak-time statement about its findings.
"Since this amounts to a significant violation of our regulations, we are instructing the corporation to transmit a announcement of our findings against it on BBC2 at 9pm, with a schedule to be finalised," it said.
'Possibility to Erode Credibility'
The watchdog's report declared: "Our investigation determined that the documentary's omission to reveal that the voice's father occupied a position in the Hamas-run authority was materially misleading.
"This implied that the viewers did not have essential details which may have been extremely pertinent to their judgment of the narrator and the details he shared.
"Trust is at the heart of the connection between a broadcaster and its public, notably for a state-funded media outlet such as the public broadcaster.
"This error had the risk to damage the exceptionally strong amounts of confidence that viewers would have placed in a BBC factual programme about the Gaza conflict."
The film was pulled from iPlayer in February after the presenter's familial connections emerged, and in this past July an corporation's own inquiry concluded it breached the organization's editorial guidelines on factual correctness.
A corporation official said: "The regulator's decision is in accordance with the findings of the corporation's inquiry, that there was a major oversight in the programme in relation to the broadcaster's journalistic policies on truthfulness, which corresponds to Rule 2.2 of the regulator's media standards.
"We expressed regret for this and we agree with the authority's determination in full. We will comply with the sanction as soon as the schedule and wording are finalised."
