The BBC committed a "serious breach" of industry standards by omitting to mention that the voice of a film about the Gaza conflict was the son of a Hamas official, as determined by UK media regulator Ofcom.
An inquiry by the media regulator into Gaza: How to Survive a Warzone has found that the documentary was "significantly deceptive".
The head of the BBC had earlier expressed regret, stating there had been "a serious error in relation to accuracy".
Ofcom has instructed the broadcaster to transmit a peak-time declaration about its decisions.
"Given this constitutes a significant violation of our code, we are ordering the broadcaster to broadcast a announcement of our determinations against it on BBC Two at 21:00, with a date to be determined," the regulator stated.
The watchdog's announcement said: "Our investigation found that the programme's failure to disclose that the narrator's male guardian held a post in the Hamas-run government was significantly deceptive.
"Consequently that the audience did not have vital facts which may have been extremely pertinent to their assessment of the voice and the information he provided.
"Credibility is at the center of the connection between a television network and its viewers, notably for a state-funded media outlet such as the public broadcaster.
"This oversight had the possibility to erode the very considerable degrees of confidence that audiences would have invested in a factual film from the broadcaster about the Israel-Gaza war."
The documentary was removed from the BBC's streaming service in February after the presenter's personal associations emerged, and in this past July an broadcaster's internal assessment concluded it violated the broadcaster's journalistic standards on accuracy.
A representative for the broadcaster said: "The regulator's decision is in line with the conclusions of Peter Johnston's review, that there was a major oversight in the documentary in relation to the broadcaster's journalistic policies on accuracy, which aligns with clause 2.2 of the authority's broadcasting regulations.
"We issued an apology for this and we agree with the authority's determination in its entirety. We will adhere to the sanction as soon as the schedule and wording are confirmed."
Elena Voss is a seasoned journalist and editor with over a decade of experience in digital media, specializing in global affairs and tech trends.