A crocodile at a Ukrainian zoo is undergoing tests and may have to have surgery after eating a visitor's mobile phone, the chief veterinarian at the zoo has said.

The crocodile swallowed the phone of a woman who was trying to photograph it last December at the Dnipropetrovsk oceanarium.

The 14-year-old reptile named Gena is now refusing food and acting lifeless.

Gena cannot eat, swim, or interact with fellow crocodiles.