Copied this from: http://www.ava.gov.sg/AnimalsPetSector/CITESEndangeredSpecies/
Singapore does not allow the keeping of exotic pets such as
reptiles, amphibians and primates as pets for the following
reasons:
* They may introduce and spread diseases to humans and domestic
animals.
* Collection of wild animals for trading will lead to ecosystem
imbalance and threaten the survival of endangered species.
* The welfare of the animals may be compromised due to reasons such
as unsuitable living conditions, poor diet and pet owner's lack of
knowledge of the proper care for the animal.
* Singapore's biodiversity would be greatly affected if such exotic
pets were released in the wild, as most of them are
non-native.
* If the animal escapes, it may cause nuisance, fear and trauma to
the general public.
Some examples of exotic pets include star tortoises, iguanas,
tarantulas, snakes, salamanders, slow lorises etc. For a list of
pets that are approved to be kept in Singapore, please click
here.
Maybe if you really have the tortise interests at heart, you might
wish to contact them at the contacts available. Let them know it's
an adopted tortise and I don't think they'll pass any charges as
long as you declare it and allow them to 'confiscate' it
