The public service broadcaster committed a "significant breach" of media regulations by failing to disclose that the voice of a programme about the Gaza conflict was the child of a Hamas official, as determined by regulatory body Ofcom.
An probe by Ofcom into the programme Gaza: How to Survive a Warzone has concluded that the programme was "significantly deceptive".
The head of the BBC had previously apologised, noting there had been "a significant failing in relation to truthfulness".
The regulator has directed the broadcaster to broadcast a peak-time declaration about its decisions.
"Given this constitutes a major infringement of our regulations, we are instructing the corporation to air a message of our findings against it on BBC2 at 21:00, with a schedule to be determined," it said.
'Potential to Undermine Confidence'
The watchdog's report declared: "Our probe concluded that the documentary's failure to disclose that the voice's parent served in a role in the Hamas-run authority was substantially inaccurate.
"This implied that the viewers did not have vital facts which may have been very significant to their assessment of the presenter and the content he provided.
"Trust is at the heart of the connection between a broadcaster and its public, notably for a public service broadcaster such as the British Broadcasting Corporation.
"This error had the risk to erode the exceptionally strong levels of confidence that viewers would have invested in a documentary produced by the BBC about the conflict in Gaza."
The programme was withdrawn from the online platform in last February after the presenter's familial connections emerged, and in this past July an broadcaster's internal assessment found it violated the corporation's content policies on accuracy.
A representative for the broadcaster commented: "The authority's determination is in accordance with the conclusions of Peter Johnston's review, that there was a serious error in the film in relation to the broadcaster's journalistic policies on truthfulness, which corresponds to regulation 2.2 of Ofcom's Broadcasting Code.
"We issued an apology for this and we comply with the authority's determination in complete. We will follow the directive as soon as the date and wording are confirmed."
