The BBC engaged in a "serious breach" of media regulations by not revealing that the presenter of a film about Gaza was the son of a Hamas official, as determined by regulatory body Ofcom.
An probe by the media regulator into the documentary titled Gaza: How to Survive a Warzone has concluded that the documentary was "substantially inaccurate".
The chief executive of the broadcaster had previously apologised, noting there had been "a major oversight in relation to accuracy".
Ofcom has ordered the broadcaster to air a peak-time declaration about its findings.
"As this represents a serious breach of our rules, we are instructing the BBC to transmit a message of our conclusions against it on BBC Two at 21:00, with a timing to be determined," the regulator stated.
'Risk to Undermine Trust'
The regulator's report stated: "The inquiry we conducted found that the documentary's omission to reveal that the voice's parent served in a post in the Hamas-controlled authority 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 content he shared.
"Credibility is at the core of the bond between a broadcaster and its viewers, notably for a national broadcasting corporation such as the public broadcaster.
"This failing had the risk to damage the significantly high amounts of credibility that audiences would have invested in a BBC factual programme about the Gaza conflict."
The documentary was removed from the BBC's streaming service in February after the boy's familial connections came to light, and in July an corporation's own inquiry concluded it infringed the organization's editorial guidelines on truthfulness.
A representative for the broadcaster said: "The authority's determination is in accordance with the results of the corporation's inquiry, that there was a significant failing in the programme in relation to the corporation's content standards on truthfulness, which aligns with Rule 2.2 of the regulator's media standards.
"We have apologised for this and we accept Ofcom's decision in full. We will comply with the sanction as soon as the timing and language are confirmed."
