The BBC has defended itself against critics of David Attenborough's Frozen Planet who claim that the filmmakers faked scenes of the birth of polar bear cubs in the series' fifth episode. The broadcaster, while acknowledging that the scenes were not shot in the arctic but in a Netherlands zoo, said that the filmmakers had complied with BBC guidelines that permit the use of captive animals when filming them in the wilds might prove Dangerous. In a filmed interview on the Frozen Planet website, producer Kathryn Jeffs explains that there was no way cameras could have been placed in a wild den. "Even if we could, you wouldn't want to disturb the polar bears by getting that close." Attenborough added that if a cameraman had entered a wild den, the mother "would either have killed the cub or she would have killed the cameraman." And Andrew Jackson, head of the BBC's natural history unit, observed in an interview with Britain's Guardian that all such nature films involve a degree of manipulation. "There are times when the shots do not always happen in that particular order, but that is filmmaking," he said, adding, "That film took four years to make and we produced an hour out of it. Through that we made some choices, guided by very strong guidelines that say you must never deceive or mislead the audience, and we don't do that." But Jim Shelley, the TV critic of the London Daily Mail , commented today (Tuesday) that Attenborough ought to "recognize that what he and the BBC did was duplicitous and simply apologize."