Nick, Surya and Takeshi were illegal immigrants who were put on a plane home yesterday. They had resided in Singapore for years and were sent back to their own country for good - on a Singapore Airlines flight, no less.

But why the VIP treatment?

Nick and his friends are three of 51 Indian star tortoises found to have been illegally trafficked here.

This is the largest number of Indian star tortoises - coveted for their star-patterned shells - to be repatriated from Singapore.

Their striking, intricate appearances make them a target for poachers, who are often part of organised crime rings that profit from animal trafficking.

The lucky few saved by the Animal Concerns Research and Education Society (Acres) are just a fraction of the estimated 10,000 to 20,000 annually taken from the wild to meet the international demand for exotic pets.

Acres has cared for the tortoises for more than eight years at its premises in Jalan Lekar in western Singapore. The organisation has spared no expense to provide varied and tailored diets for the tortoises, along with intensive veterinary care and healthy environmental conditions to keep them fit for travel.

Partner organisation Wildlife SOS India was due to meet the creatures after their 41/2-hour flight to Bangalore, India.

They will be quarantined, monitored, tagged with transmitters and released into a protected reserve in Karnataka state.

"I am relieved that these tortoises are finally going back to where they belong," said Mr Kartick Satyanarayan, co-founder and CEO of Wildlife SOS.

The tortoises were saved from a variety of places in Singapore such as roadsides, local households, where they were ill-treated, and in the briefcases of smugglers.

"The odds never favoured us, but our perseverance and sheer will, together with support from Wildlife SOS India, paved the way for us to repatriate these animals," said Ms Anbarasi Boopal, deputy chief executive of Acres, adding that this is not the first time that star tortoises have been repatriated.

Related Story Man gets 1 month's jail for smuggling 22 live star tortoises into Singapore

Related Story AVA inspectors share tales of hunting down illegal wildlife owners

The Indian star tortoise is not native to or suited to living in Singapore as it struggles to cope with its humid environment. The species is native to Gujarat and Rajasthan in north-western India, and a small area of south-eastern Pakistan, which are cooler, arid regions.

However, according to Acres, they are often kept illegally as pets in Singapore and not cared for properly. Owners often feed them supermarket-bought vegetables, which do not come with the calcium and vitamins required to keep their shells healthy.

Little is known about how to best care for and feed Indian star tortoises.

The 51 kept at Acres were fed vegetables and flowers, with additional calcium and vitamin supplements.

The organisation found that some of the tortoises were suffering from soft shells or organ failure as their shells had not grown big enough to house their bodies.

It cost Acres $6,000 a month to care for the 51 tortoises and another $1,000 per tortoise to send them back to India in a special cargo crate.

The Indian star tortoise is currently listed as "vulnerable" on the "red list" of endangered species of the International Union for Conservation of Nature, one step down from "endangered".

Acres continues to care for other wild species rescued from the illegal wildlife trade, such as red-footed tortoises, pig-nosed turtles, green iguanas, snapping turtles and sugar gliders, among others.

Acres's Animal Crime Investigation Unit also probes and monitors the illegal wildlife trade in Singapore, working closely with the Agri-Food and Veterinary Authority of Singapore to tackle the issue.