The BBC engaged in a "significant breach" of broadcasting rules by omitting to mention that the voice of a programme about Gaza was the offspring of a Hamas administrator, as determined by regulatory body Ofcom.
An investigation by the broadcasting watchdog into the documentary titled Gaza: How to Survive a Warzone has determined that the documentary was "materially misleading".
The BBC's director general had previously apologised, noting there had been "a major oversight in relation to accuracy".
The authority has instructed the BBC to broadcast a evening announcement about its decisions.
"Since this amounts to a serious breach of our regulations, we are instructing the broadcaster to transmit a message of our conclusions against it on BBC2 at nine o'clock in the evening, with a timing to be determined," the statement read.
'Potential to Undermine Trust'
The authority's statement said: "Our investigation determined that the programme's lack of disclosure that the presenter's parent served in a role in the Hamas-controlled government was significantly deceptive.
"It meant that the audience did not have critical information which may have been very significant to their assessment of the voice and the information he presented.
"Confidence is at the core of the bond between a television network and its public, notably for a national broadcasting corporation such as the BBC.
"This failing had the possibility to undermine the significantly high levels of credibility that audiences would have invested in a BBC factual programme about the conflict in Gaza."
The programme was removed from iPlayer in last February after the presenter's family links were revealed, and in the month of July an broadcaster's internal assessment found it violated the corporation's journalistic standards on truthfulness.
A BBC spokesperson commented: "The authority's determination is in line with the results of Peter Johnston's review, that there was a major oversight in the programme in relation to the BBC's Editorial Guidelines on factual correctness, which corresponds to clause 2.2 of the regulator's media standards.
"We issued an apology for this and we accept the regulator's ruling in full. We will comply with the penalty as soon as the schedule and wording are finalised."
