The illegal transportation of feral pigs from regions west of the escarpment into the Illawarra is an "historical and ongoing practice", according to the region's lands services organisation.
South East Local Land Services (SELLS) senior biosecurity officer Charlie Signorelli said while there was no major established feral pig population in the Illawarra, SELLS was ever vigilant for hunters attempting to relocate the pests.
He said previously, criminals from the Dapto and Barrack Heights areas had been found to be trapping feral pigs in the Wollondilly and Wingecarribee shires, where the animals are a problem, and bringing them to the coast.
"From time to time you do get reports ... [of] people bringing pigs into the system," Mr Signorelli said.
"Pig hunters go out west and tend to want to bring the sport closer to home.
"People also catch pigs and tend to keep them for human consumption or breed them and that's a highly illegal act."
Maximum penalties under the Local Land Services Act 2013 range from $2000 for keeping feral pigs in captivity to $5500 for releasing them and $22,000 for transporting them.
Three men pleaded guilty in Campbelltown court after police found one dead and two live pigs in their ute in Bathurst last year.
Sporting Shooters Association of Australia Illawarra branch president Mark Banasiak said he struggled to understand why hunters would want to relocate feral pigs into the Illawarra.
"I've never heard of it being done and I wouldn't want to be the one doing it because feral pigs are not particularly nice animals," Mr Banasiak said.
The warning comes as feral pig numbers have ballooned across the Southern Highlands because of improved seasonal conditions.
Mr Signorelli said so far this year, 83 pigs had been caught at 13 trapping sites in the Highlands.
He said pigs tended to follow river systems, and naturalised populations had been found in parts of the Shoalhaven.
"When you look at the Highlands you've got to look at the fact [there is a] continuation of river corridors ... and you get pig activity ... gravitating up around riparian areas," Mr Signorelli said.
SELLS is encouraging all members of the community who notice any feral pig activity to report it to its offices.