The BBC committed a "major breach" of industry standards by omitting to mention that the voice of a programme about the Gaza situation was the offspring of a Hamas representative, as ruled by UK media regulator Ofcom.
An probe by the broadcasting watchdog into Gaza: How to Survive a Warzone has concluded that the film was "materially misleading".
The chief executive of the broadcaster had already issued an apology, noting there had been "a serious error in relation to accuracy".
The authority has directed the BBC to transmit a evening statement about its findings.
"Since this amounts to a serious breach of our regulations, we are directing the broadcaster to broadcast a message of our determinations against it on the BBC's second channel at 9pm, with a date to be finalised," the regulator stated.
'Potential to Undermine Confidence'
The authority's statement stated: "Our probe found that the programme's failure to disclose that the voice's parent held a role in the Hamas-controlled administration was substantially inaccurate.
"This implied that the public did not have critical information which may have been highly relevant to their assessment of the presenter and the content he provided.
"Credibility is at the core of the connection between a media organization and its audience, particularly for a national broadcasting corporation such as the BBC.
"This error had the potential to undermine the significantly high levels of trust that viewers would have placed in a documentary produced by the BBC about the Israel-Gaza war."
The documentary was withdrawn from iPlayer in February after the presenter's family links were revealed, and in July an corporation's own inquiry determined it violated the corporation's editorial guidelines on accuracy.
A BBC spokesperson commented: "The authority's determination is in agreement with the conclusions of the corporation's inquiry, that there was a significant failing in the programme in relation to the BBC's Editorial Guidelines on truthfulness, which aligns with regulation 2.2 of Ofcom's Broadcasting Code.
"We have apologised for this and we accept the authority's determination in full. We will adhere to the sanction as soon as the schedule and wording are determined."
