The public service broadcaster engaged in a "major breach" of media regulations by not revealing that the voice of a programme about the Gaza situation was the son of a Hamas administrator, as determined by regulatory body Ofcom.
An probe by the broadcasting watchdog into the programme Gaza: How to Survive a Warzone has determined that the programme was "significantly deceptive".
The head of the BBC had previously apologised, saying there had been "a serious error in relation to truthfulness".
The authority has directed the broadcaster to transmit a prime-time statement about its findings.
"As this represents a serious breach of our regulations, we are instructing the corporation to broadcast a announcement of our conclusions against it on BBC2 at 9pm, with a timing to be finalised," it said.
'Risk to Damage Credibility'
The regulator's announcement declared: "The inquiry we conducted concluded that the documentary's failure to disclose that the voice's father served in a position in the Hamas-controlled administration was materially misleading.
"This implied that the viewers did not have essential details which may have been highly relevant to their judgment of the presenter and the information he provided.
"Credibility is at the heart of the bond between a broadcaster and its audience, particularly for a state-funded media outlet such as the public broadcaster.
"This failing had the possibility to erode the significantly high degrees of credibility that viewers would have placed in a BBC factual programme about the Israel-Gaza war."
The documentary was withdrawn from iPlayer in last February after the presenter's family links were revealed, and in July an corporation's own inquiry found it infringed the broadcaster's content policies on factual correctness.
A BBC spokesperson said: "The regulator's decision is in accordance with the findings of the corporation's inquiry, that there was a serious error in the programme in relation to the corporation's content standards on factual correctness, which corresponds to regulation 2.2 of the authority's broadcasting regulations.
"We have apologised for this and we agree with Ofcom's decision in complete. We will follow the sanction as soon as the timing and wording are confirmed."
