Hundreds of Australian greyhounds are being exported every year to racetracks in Macau and mainland China, where they face mistreatment, abuse and death.

Documents obtained under freedom of information rules by international lobby group Grey2K have revealed NSW is the biggest exporter of the dogs, sending more than 110 in just four months, with most of them under two years old.

Race for survival: The Canidrome greyhound racing stadium in Macau.

The group's president, Christine Dorchak, has written to the federal government calling for a ban on the live export of Australian greyhounds because of the likelihood they will be mistreated and killed if they were considered not good enough.

The Sun-Herald has reported thousands of submissions were sent to the state parliamentary inquiry into the greyhound industry, many of which raised issues of animal welfare, including the use of live animals as bait and the disappearance of thousands of puppies every year.