Dozens of young elephants are fed, nursed and cared for at the orphanage. Many juvenile animals wander from their herds or get lost searching for water during dry seasons and end up at Pinnawala.
There is a strong conservation lobby in Sri Lanka which fiercely resists the export of the country's iconic wildlife. Elephants are one of the 'big five' creatures which draw tourists in their thousands to see the animals in their natural environment. The other star attractions are sloth bears, leopards and blue and sperm whales.
In their petition, the conservation groups argue that Sri Lanka's endangered species belong in the wild - and not in zoos. The Court of Appeal is being urged to quash the agreement which followed Key's visit between the Sri Lankan Government and Auckland Zoo.
The deal actually covered two elephants. The first, Anjalee, arrived last year. However the Daily News reported that opponents of the elephant deal argue that there is a growing view that zoos are not suited to the welfare of animals.