The BBC engaged in a "serious breach" of media regulations by not revealing that the voice of a programme about Gaza was the child of a Hamas official, as ruled by regulatory body Ofcom.
An investigation by the media regulator into the documentary titled Gaza: How to Survive a Warzone has concluded that the film was "substantially inaccurate".
The BBC's director general had earlier expressed regret, noting there had been "a significant failing in relation to factual correctness".
Ofcom has ordered the broadcaster to air a prime-time announcement about its decisions.
"As this represents a major infringement of our code, we are ordering the broadcaster to air a message of our determinations against it on BBC Two at 9pm, with a date to be finalised," it said.
'Risk to Erode Credibility'
The watchdog's report said: "Our investigation concluded that the documentary's failure to disclose that the voice's parent occupied a position in the Hamas-run government was substantially inaccurate.
"Consequently that the public did not have critical information which may have been highly relevant to their assessment of the voice and the content he provided.
"Confidence is at the heart of the connection between a broadcaster and its viewers, particularly for a public service broadcaster such as the public broadcaster.
"This oversight had the risk to damage the exceptionally strong amounts of credibility that viewers would have put in a factual film from the broadcaster about the Israel-Gaza war."
The documentary was pulled from the BBC's streaming service in the month of February after the boy's family links were revealed, and in this past July an corporation's own inquiry concluded it infringed the organization's content policies on accuracy.
A representative for the broadcaster said: "The Ofcom ruling is in accordance with the results of Peter Johnston's review, that there was a significant failing in the film in relation to the BBC's Editorial Guidelines on accuracy, which corresponds to clause 2.2 of the regulator's media standards.
"We expressed regret for this and we comply with the authority's determination in complete. We will follow the sanction as soon as the schedule and wording are determined."
