Brain link to bear Knut's death

Celebrity polar bear Knut died after "significant changes" happened in his brain, a post mortem exam has shown.

Berlin zoo said initial results did not show changes to any other organs.

It did not elaborate but said further tests, including bacteriological examinations, will take several days.

The four-year-old bear died on Saturday afternoon in front of visitors at the zoo, turning around several times and then falling into the water in his enclosure.

Polar bears usually live 15 to 20 years in the wild, and even longer in captivity, and the zoo is hoping the investigation will clarify what happened.