A SNAKE native to the south eastern United States was caught in Tahmoor last week.
The American corn snake is native to an area in the US from New Jersey to the Florida Keys and as far west as Utah.
They are constrictors and non venomous and range in length from 60 to 180 centimetres.
Keeping the snakes in Australia is illegal because of the threat they pose should they escape.
They are relatively easy to keep and in their native habitat hang around grain stores, hunting rats and mice.
They can be confused with a copperhead snake, although are more brightly coloured.
Wollondilly Shire Council this week warned the snakes could cause significant damage to the local environment.
Last week a snake handler was called out to Tahmoor by a resident who had sighted a "white and orange weird looking python," said a council spokesperson.
The snake is in the NSW Department of Primary Industries top 10 non-native pest animals and is considered one of the most unwanted exotic pests.
The snakes can disrupt ecosystems, introduce diseases, prey on native animals and compete with them for limited resources.
The corn snake is a successful invasive species and non-native populations of corn snake have established in the Cayman Islands, the Virgin Islands and the Bahamas.
If you see an American corn snake or other non-native species, please report it to the NSW DPI by phone on 1800 680 244 or through their website, www.dpi.nsw.gov.au/biosecurity/report