The British broadcaster committed a "major breach" of industry standards by not revealing that the voice of a film about the Gaza conflict was the offspring of a Hamas representative, as determined by British broadcasting authority Ofcom.
An probe by Ofcom into the programme Gaza: How to Survive a Warzone has found that the documentary was "substantially inaccurate".
The head of the BBC had earlier expressed regret, noting there had been "a serious error in relation to factual correctness".
The regulator has directed the corporation to broadcast a evening announcement about its findings.
"Given this constitutes a serious breach of our regulations, we are ordering the BBC to transmit a statement of our findings against it on the BBC's second channel at 21:00, with a timing to be confirmed," it said.
'Risk to Damage Credibility'
The authority's report said: "Our probe concluded that the programme's lack of disclosure that the voice's parent occupied a post in the Hamas-controlled administration was materially misleading.
"Consequently that the viewers did not have vital facts which may have been very significant to their assessment of the voice and the details he provided.
"Credibility is at the core of the bond between a television network and its audience, particularly for a state-funded media outlet such as the BBC.
"This oversight had the risk to damage the exceptionally strong levels of credibility that the public would have placed in a documentary produced by the BBC about the conflict in Gaza."
The programme was removed from iPlayer in February after the presenter's personal associations were revealed, and in the month of July an internal BBC review concluded it violated the organization's editorial guidelines on factual correctness.
A representative for the broadcaster stated: "The Ofcom ruling is in accordance with the findings of Peter Johnston's review, that there was a serious error in the film in relation to the broadcaster's journalistic policies on accuracy, which reflects clause 2.2 of the regulator's media standards.
"We have apologised for this and we accept Ofcom's decision in full. We will follow the directive as soon as the timing and wording are determined."
