Knut may be the first polar bear to have graced the cover of Vanity Fair magazine, but such fame isn't enough to stop animal rights activists from demanding castration for Berlin's ursine celebrity.
Such a fate seems like the unkindest cut of all for a polar bear who has not only just found a mate after years in solitary confinement; but who was also abandoned by his mother at birth and has been separated from his beloved keeper.
Knut's lonely circumstances only ended in September after he was introduced to Giovanna, a lively female brought to join him from Munich. Since then visitors to Berlin Zoo have been treated to a daily spectacle of the two animals playing together and looking like they are loving every minute of it.
However, the German branch of the animal rights group, People for the Ethical Treatment of Animals, insisted yesterday that as the two bears shared the same grandfather, their future offspring and the future of captive polar bears in general were at serious risk through the possibility of their inbreeding.
"Knut fans should be aware that only Knut's castration would allow the long-term cohabitation of Giovanna and Knut" insisted Frank Albrecht, PETA's zoo expert with more than a hint of schadenfreude. "All other hopes and desires would bring the polar bear population in captivity to its pre-programmed demise even more rapidly", he added.
PETA campaigns to prevent zoos from keeping polar bears and has consistently argued that there are "massive problems" in keeping the animals in captivity. These apparently, include the risk of ursine idiocy as a result of sex in the same family. "Inbreeding reduces genetic diversity and there is a danger of inbreeding depression in future offspring," Mr Albrecht insisted.
The suggestion caused howls of protest in Germany's popular press yesterday. Berlin Zoo refused to comment on PETA's claim. Heiner Klös, its bear expert, pointed out that Giovanna was only on loan to Berlin and that she was scheduled to return to Munich Zoo in the summer anyway, when renovation work on her enclosure would be finished.
Berlin's Knut fan club has nevertheless been campaigning vigorously for Giovanna to stay on in Berlin as the two bears now appear to have adapted well to each other despite a difficult beginning when Knut was hit on the nose by his female guest. However, there have been no reports so far that the two animals have attempted to mate.
Since his birth in 2006 to a maltreated circus bear who subsequently abandoned him, Knut has earned well in excess of €10m for Berlin Zoo. His enclosure is permanently surrounded during opening hours and millions of Knut cuddly toys based on what he looked like as a cub have been sold to an adoring public. His popularity led to him being formally adopted by Germany's Environment Minister and to his appearance on Vanity Fair's cover.
But Knut has since suffered the death of Thomas Dörflein in 2008, the keeper who raised him from birth with Elvis lullabies strummed on his guitar, and charges by animal psychologists that he is a psychopath incapable of relationships with other bears because he is surrounded by humans.
Last year, the polar bear was in danger of becoming a victim of the credit crunch after the city said it could no longer afford to keep him. But Giovanna's arrival in Knut's enclosure last year appears to have reversed the bear's tragic fortunes and dramatically increased takings at Berlin Zoo.
If the advice of modern biologists is adhered to then Knut will also escape castration. "It does not make sense," said Dr Katarina Jewgenow, head of reproductive biology at the Leipzig Institute for Biological Research, "Contraception is enough. Giovanna could easily be given the pill" she added.