The BBC was found to have committed a "major breach" of media regulations by not revealing that the voice of a programme about Gaza was the offspring of a Hamas official, as ruled by British broadcasting authority Ofcom.
An probe by the broadcasting watchdog into Gaza: How to Survive a Warzone has concluded that the film was "significantly deceptive".
The BBC's director general had earlier expressed regret, noting there had been "a significant failing in relation to factual correctness".
The authority has instructed the BBC to air a peak-time announcement about its findings.
"As this represents a significant violation of our code, we are ordering the broadcaster to transmit a announcement of our findings against it on BBC2 at 9pm, with a date to be confirmed," the statement read.
'Risk to Erode Trust'
The regulator's statement declared: "The inquiry we conducted concluded that the programme's lack of disclosure that the narrator's parent occupied a position in the Hamas-controlled government was substantially inaccurate.
"Consequently that the viewers did not have essential details which may have been extremely pertinent to their evaluation of the presenter and the information he provided.
"Trust is at the core of the connection between a broadcaster and its public, particularly for a public service broadcaster such as the public broadcaster.
"This oversight had the possibility to erode the very considerable levels of confidence that audiences would have placed in a BBC factual programme about the Israel-Gaza war."
The film was removed from the online platform in February after the narrator's family links emerged, and in July an internal BBC review concluded it violated the broadcaster's content policies on accuracy.
A representative for the broadcaster commented: "The regulator's decision is in agreement with the results of Peter Johnston's review, that there was a significant failing in the programme in relation to the BBC's Editorial Guidelines on truthfulness, which corresponds to Rule 2.2 of the regulator's media standards.
"We expressed regret for this and we agree with the authority's determination in full. We will comply with the penalty as soon as the timing and language are confirmed."
