The BBC engaged in a "major breach" of industry standards by not revealing that the narrator of a film about Gaza was the son of a Hamas administrator, as determined by regulatory body Ofcom.
An inquiry by the media regulator into the programme Gaza: How to Survive a Warzone has found that the programme was "significantly deceptive".
The head of the BBC had previously apologised, noting there had been "a serious error in relation to accuracy".
The authority has instructed the broadcaster to transmit a prime-time declaration about its conclusions.
"Given this constitutes a major infringement of our regulations, we are directing the corporation to air a message of our conclusions against it on BBC Two at nine o'clock in the evening, with a schedule to be determined," the regulator stated.
'Risk to Erode Trust'
The authority's announcement said: "Our investigation determined that the documentary's omission to reveal that the presenter's father held a position in the Hamas-run authority was substantially inaccurate.
"Consequently that the viewers did not have vital facts which may have been highly relevant to their evaluation of the presenter and the information he presented.
"Credibility is at the center of the bond between a television network and its public, especially for a state-funded media outlet such as the BBC.
"This failing had the potential to undermine the significantly high amounts of confidence that viewers would have placed in a factual film from the broadcaster about the Gaza conflict."
The programme was pulled from iPlayer in last February after the presenter's personal associations were revealed, and in July an corporation's own inquiry concluded it infringed the broadcaster's content policies on factual correctness.
A representative for the broadcaster stated: "The Ofcom ruling is in agreement with the conclusions of the corporation's inquiry, that there was a serious error in the programme in relation to the broadcaster's journalistic policies on factual correctness, which corresponds to regulation 2.2 of the regulator's media standards.
"We issued an apology for this and we agree with the regulator's ruling in its entirety. We will comply with the directive as soon as the date and language are finalised."
