The BBC was found to have committed a "serious breach" of industry standards by not revealing that the narrator of a documentary about the Gaza situation was the son of a Hamas representative, as ruled by regulatory body Ofcom.
An investigation by Ofcom into the programme Gaza: How to Survive a Warzone has found that the film was "substantially inaccurate".
The BBC's director general had already issued an apology, noting there had been "a significant failing in relation to truthfulness".
The regulator has instructed the broadcaster to transmit a peak-time announcement about its decisions.
"Since this amounts to a serious breach of our rules, we are ordering the corporation to transmit a message of our findings against it on BBC2 at nine o'clock in the evening, with a timing to be finalised," it said.
'Risk to Undermine Trust'
The watchdog's report declared: "Our probe determined that the documentary's omission to reveal that the voice's father held a role in the Hamas-run authority was significantly deceptive.
"This implied that the viewers did not have essential details which may have been very significant to their judgment of the presenter and the content he shared.
"Confidence 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 erode the very considerable amounts of trust that viewers would have put in a documentary produced by the BBC about the Gaza conflict."
The programme was removed from the online platform in February after the narrator's family links came to light, and in the month of July an internal BBC review concluded it breached the broadcaster's editorial guidelines on factual correctness.
A BBC spokesperson stated: "The authority's determination is in line with the findings of Peter Johnston's review, that there was a serious error in the programme in relation to the corporation's content standards on truthfulness, which corresponds to clause 2.2 of the authority's broadcasting regulations.
"We expressed regret for this and we agree with the authority's determination in its entirety. We will comply with the directive as soon as the timing and language are determined."
