The BBC committed a "significant breach" of broadcasting rules by failing to disclose that the presenter of a programme about Gaza was the child of a Hamas administrator, as ruled by UK media regulator Ofcom.
An inquiry by the broadcasting watchdog into Gaza: How to Survive a Warzone has concluded that the documentary was "materially misleading".
The BBC's director general had already issued an apology, noting there had been "a significant failing in relation to factual correctness".
The regulator has directed the broadcaster to transmit a evening announcement about its findings.
"Since this amounts to a serious breach of our code, we are ordering the BBC to transmit a announcement of our findings against it on BBC Two at 21:00, with a timing to be confirmed," the regulator stated.
'Potential to Undermine Confidence'
The regulator's announcement stated: "Our investigation found that the documentary's omission to reveal that the presenter's parent occupied a post in the Hamas-controlled authority was materially misleading.
"It meant that the audience did not have essential details which may have been very significant to their assessment of the voice and the content he shared.
"Credibility is at the core of the bond between a broadcaster and its audience, notably for a state-funded media outlet such as the public broadcaster.
"This failing had the possibility to erode the very considerable amounts of credibility that viewers would have put in a documentary produced by the BBC about the Gaza conflict."
The film was withdrawn from the BBC's streaming service in February after the narrator's family links emerged, and in the month of July an broadcaster's internal assessment concluded it breached the broadcaster's editorial guidelines on factual correctness.
A corporation official said: "The Ofcom ruling is in accordance with the conclusions of Peter Johnston's review, that there was a serious error in the programme in relation to the corporation's content standards on factual correctness, which reflects clause 2.2 of the authority's broadcasting regulations.
"We have apologised for this and we comply with Ofcom's decision in complete. We will adhere to the directive as soon as the schedule and wording are finalised."
