THE POST-MORTEM results for Germany’s celebrity polar bear Knut have been released, and show that he died from drowning after collapsing due to swelling of his brain and falling into his enclosure’s pool.

Pathologist Claudia Szentiks said a necropsy of the four-year-old bear who died suddenly two weeks ago showed he was suffering from encephalitis.

This is an irritation and swelling of the brain and was probably brought on by an infection.

Experts don’t know exactly what caused the swelling, but have ruled out rabies, botulism and bovine spongiform encephalopathy, also known as mad cow disease.

Szentiks rejected allegations from animal-rights groups that Knut was traumatised by living in a zoo environment, saying that there were no indications of any chronic stress.

Even if Knut had not drowned, the pathologist said that he would not have survived the damage from the encephalitis.

Knut died on 19 March  in front of visitors at Berlin zoo, who saw him turning around several times and then falling into the water in his enclosure.

His was a very premature death – polar bears usually live 15 to 20 years in the wild and longer in captivity.

Knut, who was born in December 2006 at the zoo, was rejected by his mother at birth — along with his twin brother, who only survived a couple of days. His main caregiver, Thomas Doerflein, camped out at the zoo to give the  cub his bottle every two hours. Sadly, Doerflein died in 2008 of a heart attack.

Throughout his short life, Knut appeared on magazine covers, in a film and on mountains of merchandise.

- AP