The BBC committed a "significant breach" of industry standards by not revealing that the presenter of a film about Gaza was the offspring of a Hamas representative, as ruled by regulatory body Ofcom.
An inquiry by Ofcom into the documentary titled Gaza: How to Survive a Warzone has concluded that the programme was "materially misleading".
The head of the BBC had earlier expressed regret, stating there had been "a significant failing in relation to factual correctness".
The authority has directed the broadcaster to transmit a evening statement about its conclusions.
"As this represents a major infringement of our rules, we are instructing the broadcaster to transmit a message of our findings against it on BBC2 at 9pm, with a date to be finalised," it said.
'Potential to Undermine Confidence'
The watchdog's announcement said: "Our investigation concluded that the documentary's failure to disclose that the voice's parent occupied a post in the Hamas-controlled government was significantly deceptive.
"Consequently that the viewers did not have critical information which may have been extremely pertinent to their evaluation of the voice and the content he shared.
"Credibility is at the core of the relationship between a broadcaster and its public, notably for a public service broadcaster such as the BBC.
"This failing had the risk to damage the exceptionally strong levels of credibility that audiences would have placed in a BBC factual programme about the Gaza conflict."
The film was removed from the BBC's streaming service in February after the narrator's personal associations emerged, and in this past July an corporation's own inquiry found it infringed the broadcaster's content policies on accuracy.
A BBC spokesperson commented: "The regulator's decision is in agreement with the findings of the corporation's inquiry, that there was a serious error in the film in relation to the BBC's Editorial Guidelines on factual correctness, which reflects regulation 2.2 of the regulator's media standards.
"We expressed regret for this and we agree with Ofcom's decision in full. We will adhere to the penalty as soon as the schedule and language are finalised."
