The BBC was found to have committed a "major breach" of broadcasting rules by omitting to mention that the narrator of a programme about Gaza was the child of a Hamas official, according to regulatory body Ofcom.
An inquiry by Ofcom into Gaza: How to Survive a Warzone has determined that the film was "materially misleading".
The BBC's director general had already issued an apology, saying there had been "a significant failing in relation to accuracy".
The authority has directed the BBC to transmit a peak-time announcement about its conclusions.
"As this represents a major infringement of our regulations, we are directing the broadcaster to broadcast a announcement of our conclusions against it on BBC2 at 9pm, with a timing to be determined," the statement read.
'Risk to Damage Credibility'
The watchdog's report stated: "Our probe found that the programme's omission to reveal that the presenter's father occupied a role in the Hamas-controlled authority was materially misleading.
"It meant that the public did not have critical information which may have been extremely pertinent to their assessment of the presenter and the details he shared.
"Confidence is at the center of the connection between a broadcaster and its viewers, notably for a public service broadcaster such as the BBC.
"This oversight had the potential to undermine the very considerable amounts of credibility that audiences would have placed in a BBC factual programme about the Israel-Gaza war."
The documentary was removed from the online platform in the month of February after the boy's personal associations were revealed, and in this past July an corporation's own inquiry concluded it violated the broadcaster's content policies on truthfulness.
A BBC spokesperson commented: "The authority's determination is in line with the results of the corporation's inquiry, that there was a serious error in the film in relation to the broadcaster's journalistic policies on factual correctness, which reflects clause 2.2 of the regulator's media standards.
"We expressed regret for this and we accept the authority's determination in full. We will comply with the directive as soon as the date and language are determined."
