The BBC engaged in a "significant breach" of media regulations by not revealing that the voice of a programme about Gaza was the son of a Hamas official, as ruled by British broadcasting authority Ofcom.
An investigation by the media regulator into Gaza: How to Survive a Warzone has determined that the programme was "substantially inaccurate".
The BBC's director general had earlier expressed regret, stating there had been "a major oversight in relation to truthfulness".
The regulator has ordered the corporation to transmit a peak-time statement about its decisions.
"As this represents a serious breach of our code, we are ordering the broadcaster to transmit a message of our findings against it on the BBC's second channel at 21:00, with a timing to be confirmed," it said.
'Potential to Undermine Credibility'
The authority's announcement said: "Our probe found that the film's omission to reveal that the narrator's parent served in a post in the Hamas-administered government was significantly deceptive.
"Consequently that the public did not have critical information which may have been very significant to their assessment of the presenter and the content he provided.
"Confidence is at the center of the connection between a media organization and its viewers, particularly for a state-funded media outlet such as the British Broadcasting Corporation.
"This error had the risk to damage the very considerable degrees of trust that the public would have invested in a factual film from the broadcaster about the Gaza conflict."
The film was removed from iPlayer in February after the boy's familial connections emerged, and in July an broadcaster's internal assessment concluded it violated the organization's content policies on factual correctness.
A representative for the broadcaster commented: "The authority's determination is in line with the conclusions of the internal assessment, that there was a serious error in the programme in relation to the broadcaster's journalistic policies on accuracy, which corresponds to clause 2.2 of the regulator's media standards.
"We expressed regret for this and we comply with the authority's determination in complete. We will adhere to the directive as soon as the timing and language are confirmed."
