A polar bear cub and the keeper who raised him are to give up the twice-daily appearances that turned them into international celebrities since the animal is now big enough to be dangerous, Berlin zoo said recently.

Confirming a report which appeared in yesterday?s Berliner Kurier newspaper, zoo curator Heiner Kloes told RBB radio that the regular morning and afternoon appearances will be stopped now that seven-month-old Knut had grown to 50 kilos .

Keeper Thomas Doerflein had slept in the same room with Knut after his birth and fed him bottles through the night after his mother rejected him. In his twice daily appearances that drew more than one million visitors, Doerflein rolled on the ground with the cub and allowed his fingers to be playfully bitten.

But Knut, 800 g at birth, has since turned into a shaggy yet powerful predator who could soon pose a serious threat to Doerflein. Zoo curator Kloes said the polar bear would continue to roam a small bear cliff enclosure on his own.