The BBC committed a "serious breach" of media regulations by omitting to mention that the presenter of a film about Gaza was the child of a Hamas administrator, according to regulatory body Ofcom.
An probe by Ofcom into Gaza: How to Survive a Warzone has concluded that the documentary was "substantially inaccurate".
The head of the BBC had previously apologised, saying there had been "a serious error in relation to factual correctness".
Ofcom has directed the broadcaster to broadcast a evening declaration about its findings.
"As this represents a significant violation of our rules, we are ordering the BBC to transmit a message of our conclusions against it on the BBC's second channel at nine o'clock in the evening, with a schedule to be finalised," the statement read.
'Possibility to Undermine Credibility'
The watchdog's statement stated: "Our probe determined that the programme's lack of disclosure that the presenter's father occupied a position in the Hamas-administered administration was significantly deceptive.
"It meant that the viewers did not have critical information which may have been very significant to their evaluation of the presenter and the content he provided.
"Trust is at the core of the bond between a media organization and its public, notably for a public service broadcaster such as the British Broadcasting Corporation.
"This oversight had the possibility to erode the very considerable amounts of trust that audiences would have placed in a factual film from the broadcaster about the conflict in Gaza."
The film was removed from iPlayer in the month of February after the presenter's familial connections emerged, and in July an broadcaster's internal assessment found it breached the organization's editorial guidelines on truthfulness.
A representative for the broadcaster stated: "The regulator's decision is in accordance with the results of the internal assessment, that there was a major oversight in the film in relation to the broadcaster's journalistic policies on truthfulness, which reflects regulation 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we agree with the authority's determination in complete. We will adhere to the directive as soon as the date and wording are finalised."
