The BBC committed a "significant breach" of industry standards by omitting to mention that the narrator of a documentary about the Gaza conflict was the son of a Hamas official, according to British broadcasting authority Ofcom.
An investigation by the media regulator into the programme Gaza: How to Survive a Warzone has determined that the programme was "substantially inaccurate".
The chief executive of the broadcaster had previously apologised, noting there had been "a significant failing in relation to truthfulness".
The regulator has ordered the corporation to transmit a evening statement about its findings.
"As this represents a major infringement of our rules, we are directing the broadcaster to transmit a announcement of our conclusions against it on BBC Two at nine o'clock in the evening, with a timing to be finalised," the statement read.
'Possibility to Undermine Credibility'
The authority's report stated: "The inquiry we conducted concluded that the film's omission to reveal that the presenter's male guardian served in a position in the Hamas-administered government was substantially inaccurate.
"Consequently that the audience did not have essential details which may have been very significant to their assessment of the voice and the information he provided.
"Credibility is at the center of the relationship between a television network and its viewers, particularly for a state-funded media outlet such as the public broadcaster.
"This error had the possibility to undermine the significantly high levels of trust that the public would have put in a documentary produced by the BBC about the Gaza conflict."
The programme was pulled from the BBC's streaming service in last February after the presenter's family links came to light, and in July an broadcaster's internal assessment concluded it breached the broadcaster's content policies on factual correctness.
A BBC spokesperson said: "The regulator's decision is in agreement with the conclusions of Peter Johnston's review, that there was a major oversight in the film in relation to the broadcaster's journalistic policies on accuracy, which reflects clause 2.2 of Ofcom's Broadcasting Code.
"We expressed regret for this and we agree with Ofcom's decision in its entirety. We will comply with the sanction as soon as the timing and language are confirmed."
