The BBC engaged in a "significant breach" of media regulations by failing to disclose that the presenter of a film about the Gaza conflict was the son of a Hamas official, as determined by British broadcasting authority Ofcom.
An inquiry by Ofcom into the programme Gaza: How to Survive a Warzone has concluded that the programme was "significantly deceptive".
The head of the BBC had already issued an apology, noting there had been "a serious error in relation to factual correctness".
The regulator has instructed the broadcaster to broadcast a peak-time announcement about its decisions.
"Since this amounts to a significant violation of our code, we are directing the corporation to transmit a announcement of our findings against it on BBC2 at 21:00, with a timing to be confirmed," the statement read.
The authority's statement declared: "Our investigation concluded that the documentary's failure to disclose that the narrator's father served in a position in the Hamas-administered authority was substantially inaccurate.
"Consequently that the audience did not have critical information which may have been extremely pertinent to their evaluation of the presenter and the information he presented.
"Confidence is at the core of the bond between a media organization and its public, especially for a public service broadcaster such as the public broadcaster.
"This oversight had the risk to erode the significantly high amounts of confidence that the public would have placed in a BBC factual programme about the conflict in Gaza."
The documentary was withdrawn from the BBC's streaming service in February after the presenter's family links emerged, and in the month of July an corporation's own inquiry determined it infringed the corporation's content policies on accuracy.
A representative for the broadcaster commented: "The authority's determination is in agreement with the conclusions of Peter Johnston's review, that there was a significant failing in the documentary in relation to the BBC's Editorial Guidelines on truthfulness, which reflects Rule 2.2 of the regulator's media standards.
"We issued an apology for this and we accept Ofcom's decision in complete. We will adhere to the sanction as soon as the timing and wording are determined."
Elena Hartwell is a tech enthusiast and lifestyle writer exploring the intersection of innovation and well-being.