Members of the public have been warned that dropping their possessions when visiting zoos could pose a fatal risk to animals.
The warning followed the death of a polar bear at a Stuttgart zoo who is thought to have died after eating a coat and bag he found in his enclosure.
The 25-year-old polar bear, named Anton, died of severe intestinal injuries after apparently swallowing a jacket or bag, the zoo said.
Keepers noticed the bear acting strangely last week and observed him spitting out bits of material. The bear, who could have lived for another 15 years, was given vomit-inducing drugs.
Despite throwing up more pieces of the bag and jacket, he died of severe internal injuries and inflammation.
The zoo said it is unclear how the items came to be in Anton's enclosure, which is surrounded by an electric fence, or why he decided to eat them rather than simply tear them apart as he normally would.
The death is not the first tragedy of its type at the zoo.
Charly, the last elephant seal in the zoo, died after swallowing a teddy bear and a hippopotamus called Egon died several years ago after swallowing a tennis ball.
According to The Times around 200 children’s shoes have been discovered in the polar bear enclosure alone during the last 20 years, along with a wide variety of other items including 'countless' hats, phones and glasses.
The zoo appealed to visitors to report the loss of large objects to allow zookeepers to remove them quickly. It says it previously lost an elephant seal that swallowed a toy animal.
Practices at European zoos came under the spotlight last week after Copenhagen zoo killed a young giraffe deemed as 'surplus', before dismembering him in front of children and feeding the animal to the zoo’s lions.
The actions of the zoo were condemned as 'barbaric' by campaigners.