The British broadcaster engaged in a "significant breach" of media regulations by failing to disclose that the presenter of a programme about Gaza was the child of a Hamas official, as determined by UK media regulator Ofcom.
An probe by the broadcasting watchdog into the documentary titled Gaza: How to Survive a Warzone has concluded that the documentary was "significantly deceptive".
The BBC's director general had already issued an apology, noting there had been "a major oversight in relation to accuracy".
Ofcom has directed the BBC to transmit a peak-time declaration about its decisions.
"Since this amounts to a serious breach of our regulations, we are ordering the BBC to broadcast a statement of our conclusions against it on BBC2 at 21:00, with a schedule to be confirmed," it said.
'Risk to Undermine Trust'
The watchdog's statement declared: "Our probe concluded that the programme's lack of disclosure that the presenter's male guardian held a position in the Hamas-administered authority was materially misleading.
"This implied that the audience did not have essential details which may have been very significant to their assessment of the voice and the information he presented.
"Credibility is at the core of the bond between a television network and its viewers, particularly for a national broadcasting corporation such as the British Broadcasting Corporation.
"This oversight had the risk to damage the significantly high amounts of credibility that viewers would have put in a factual film from the broadcaster about the conflict in Gaza."
The documentary was pulled from iPlayer in February after the presenter's family links were revealed, and in July an broadcaster's internal assessment determined it violated the corporation's journalistic standards on truthfulness.
A BBC spokesperson commented: "The authority's determination is in agreement with the conclusions of Peter Johnston's review, that there was a significant failing in the film in relation to the BBC's Editorial Guidelines on truthfulness, which corresponds to regulation 2.2 of the regulator's media standards.
"We issued an apology for this and we accept the authority's determination in its entirety. We will adhere to the sanction as soon as the timing and language are finalised."
