The British broadcaster engaged in a "major breach" of broadcasting rules by not revealing that the presenter of a programme about the Gaza situation was the child of a Hamas administrator, according to UK media regulator Ofcom.
An investigation by the media regulator into the programme Gaza: How to Survive a Warzone has determined that the documentary was "materially misleading".
The BBC's director general had earlier expressed regret, stating there had been "a significant failing in relation to accuracy".
The authority has instructed the corporation to broadcast a peak-time statement about its findings.
"Given this constitutes a significant violation of our code, we are ordering the BBC to transmit a message of our determinations against it on the BBC's second channel at 21:00, with a date to be determined," the statement read.
'Possibility to Erode Trust'
The regulator's statement said: "Our investigation found that the documentary's omission to reveal that the presenter's male guardian occupied a post in the Hamas-controlled administration was materially misleading.
"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 shared.
"Credibility is at the core of the bond between a media organization and its viewers, especially for a national broadcasting corporation such as the public broadcaster.
"This error had the possibility to undermine the very considerable amounts of trust that audiences would have put in a BBC factual programme about the conflict in Gaza."
The programme was removed from the online platform in February after the presenter's family links were revealed, and in the month of July an internal BBC review concluded it infringed the broadcaster's editorial guidelines on truthfulness.
A corporation official commented: "The Ofcom ruling is in agreement with the results of the internal assessment, that there was a significant failing in the documentary in relation to the broadcaster's journalistic policies on accuracy, which aligns with clause 2.2 of the regulator's media standards.
"We have apologised for this and we agree with the regulator's ruling in its entirety. We will comply with the directive as soon as the timing and wording are finalised."
