The BBC engaged in a "major breach" of broadcasting rules by failing to disclose that the presenter of a programme about Gaza was the child of a Hamas administrator, as determined by regulatory body Ofcom.
An inquiry by the media regulator into Gaza: How to Survive a Warzone has found that the programme was "significantly deceptive".
The BBC's director general had previously apologised, saying there had been "a major oversight in relation to factual correctness".
The regulator has ordered the corporation to air a evening declaration about its conclusions.
"As this represents a major infringement of our rules, we are directing the corporation to broadcast a message of our determinations against it on BBC2 at 21:00, with a schedule to be confirmed," the statement read.
'Risk to Erode Credibility'
The regulator's announcement stated: "Our probe determined that the documentary's omission to reveal that the voice's male guardian served in a position in the Hamas-administered administration was significantly deceptive.
"This implied that the public did not have essential details which may have been highly relevant to their assessment of the voice and the details he provided.
"Credibility is at the core of the bond between a broadcaster and its public, especially for a public service broadcaster such as the BBC.
"This error had the possibility to erode the significantly high levels of confidence that audiences would have invested in a BBC factual programme about the conflict in Gaza."
The documentary was removed from the BBC's streaming service in last February after the narrator's familial connections were revealed, and in this past July an internal BBC review found it breached the organization's content policies on factual correctness.
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 factual correctness, which reflects Rule 2.2 of the authority's broadcasting regulations.
"We have apologised for this and we accept the authority's determination in complete. We will adhere to the directive as soon as the schedule and language are determined."