A salamander that lived at London Zoo for 20 years has turned out to be a new species which could be the largest amphibian in the world.

The animal, which was kept at the zoo in the Twenties and later preserved at the Natural History Museum, was thought to be a Chinese giant salamander, but tests from 17 specimens held at the museum showed it was completely a new species that was actually bigger than its cousin.

The amphibian, which has been called the South China giant salamander, was held by the museum for 74 years and is presumed to still live in the wild.

When it lived at London Zoo, scientists in the 1920s had abandoned proposals that it could be a new species.

The same salamander has now been used to define the characteristics of the new species.