It began as a fairytale: a fluffy polar bear cub gave pleasure to millions around the world after being saved from death by his keeper. Then Berlin zoo turned into a media circus and the troubled adolescent bear, said to be addicted to applause, was forcibly separated from the man who had reared him by hand.
Now the tale of Knut has ended in tragedy after his keeper, who hand-fed him milk and porridge for 150 days straight, was found dead at his apartment in Berlin.
Thomas Doerflein did not seek fame but found it through Knut, who was rejected by his mother and would have died were it not for the 44-year-old's ministrations. As Knut became a global sensation, animal rights activists argued that he should be killed because it was unnatural and cruel to keep a rejected bear alive.
Some felt vindicated when it emerged that Knut, who grew up surrounded by screaming crowds, began "crying" when short of human attention. They could scarcely have imagined the bear's global celebrity might have been equally cruel on his human carer.
Doerflein was a quiet man who had worked for the zoo since he was 16. He turned down numerous interview and chat show requests, although he appeared on the Knut DVD - just one piece of Knut paraphernalia - which revealed the extraordinary tenderness between man and bear as Doerflein played Knut the guitar and taught him to swim.
When Doerflein did speak, he sounded bewildered by the attention. "Here on my desk is a pile of love letters from around the world - they're even sending me poems and songs they've written about me," he once told the newspaper Der Tagesspiegel. "When I leave work I get besieged by young women. I'm afraid to go out there."
There was disquiet about the zoo's marketing of the bear and a rival zoo in northern Germany, which housed Knut's father, began legal action against Berlin claiming it was due a slice of Knut's fortune. If it had been a dispute over a child star, it would probably have attracted headlines about "the curse of Knut".
Now nearly two years old and an "activist" for global warming, Knut will be blissfully ignorant of his former keeper's fate. The cause of Doerflein's death is not yet known but police reportedly found no evidence of foul play or suicide. We may never know, however, just how profound an impact one polar bear had on the life of his human "father".
