The BBC was found to have committed a "significant breach" of broadcasting rules by not revealing that the narrator of a programme about the Gaza conflict was the son of a Hamas official, according to UK media regulator Ofcom.
An investigation by the media regulator into the programme Gaza: How to Survive a Warzone has found that the documentary was "materially misleading".
The head of the BBC had previously apologised, stating there had been "a serious error in relation to factual correctness".
The regulator has ordered the BBC to broadcast a peak-time declaration about its conclusions.
"Since this amounts to a major infringement of our regulations, we are directing the corporation to air a announcement of our determinations against it on BBC Two at nine o'clock in the evening, with a timing to be confirmed," it said.
'Potential to Erode Trust'
The authority's report declared: "Our investigation concluded that the film's lack of disclosure that the voice's male guardian held a post in the Hamas-administered government was significantly deceptive.
"Consequently that the viewers did not have essential details which may have been extremely pertinent to their evaluation of the narrator and the content he provided.
"Trust is at the heart of the bond between a media organization and its viewers, especially for a state-funded media outlet such as the public broadcaster.
"This error had the risk to undermine the very considerable degrees of trust that audiences would have placed in a factual film from the broadcaster about the conflict in Gaza."
The film was withdrawn from iPlayer in February after the presenter's personal associations were revealed, and in this past July an internal BBC review concluded it violated the corporation's editorial guidelines on accuracy.
A BBC spokesperson stated: "The authority's determination is in accordance with the results of the internal assessment, that there was a major oversight in the documentary in relation to the broadcaster's journalistic policies on factual correctness, which aligns with regulation 2.2 of the regulator's media standards.
"We expressed regret for this and we accept the authority's determination in complete. We will comply with the penalty as soon as the schedule and language are finalised."
