The BBC was found to have committed a "significant breach" of industry standards by not revealing that the presenter of a film about the Gaza conflict was the son of a Hamas official, as ruled by British broadcasting authority Ofcom.
An inquiry by the broadcasting watchdog into Gaza: How to Survive a Warzone has concluded that the programme was "significantly deceptive".
The head of the BBC had already issued an apology, saying there had been "a significant failing in relation to truthfulness".
The regulator has ordered the BBC to transmit a peak-time declaration about its conclusions.
"Since this amounts to a serious breach of our rules, we are instructing the BBC to transmit a statement of our conclusions against it on the BBC's second channel at nine o'clock in the evening, with a schedule to be finalised," the statement read.
'Risk to Erode Trust'
The authority's statement declared: "The inquiry we conducted found that the film's omission to reveal that the presenter's male guardian served in a role in the Hamas-controlled government was significantly deceptive.
"This implied that the viewers did not have essential details which may have been highly relevant to their evaluation of the voice and the content he provided.
"Trust is at the core of the bond between a television network and its public, especially for a national broadcasting corporation such as the public broadcaster.
"This error had the potential to undermine the very considerable amounts of credibility that viewers would have put in a BBC factual programme about the Gaza conflict."
The documentary was removed from the online platform in the month of February after the presenter's personal associations came to light, and in the month of July an internal BBC review concluded it violated the corporation's journalistic standards on factual correctness.
A BBC spokesperson said: "The regulator's decision is in accordance with the results of the internal assessment, that there was a serious error in the programme in relation to the BBC's Editorial Guidelines on accuracy, which corresponds to Rule 2.2 of the authority's broadcasting regulations.
"We have apologised for this and we comply with Ofcom's decision in complete. We will comply with the penalty as soon as the date and wording are confirmed."
