A giant exotic snail has been humanely destroyed after being found crawling across the concrete at a Brisbane container yard.

Staff called Department of Agriculture biosecurity officers after seeing the snail, described as being the size of a cricket ball, sliding slowly across the cement.

Entomologists have identified it as a giant African snail, a species which can grow up to 20 centimetres long and weigh up to a kilogram.

The species is found throughout Africa and Asia capable of destroying crops, fruit trees and native forests.

An individual snail can lay up to 1,200 eggs a year after a single mating and can live up to nine years.

Biosecurity officers humanely destroyed the exotic pest and have not found any other snails, eggs or snail trails.

They will monitor the site for a week for any further activity.

Acting regional manager Paul Nixon says the snail is also a hermaphrodite, meaning the species can quickly spread.

"They are essentially a male-female all-in-one so they can essentially lay eggs without the need for any other snail," he said.

Mr Nixon says staff at the shipping yard were surprised by the size of the snail.

"They can grow quite significantly but the impact for us is not so much around the growth but the extent that they can lay their eggs and breed quite prolifically," he said.

Mr Nixon says the species is native to Asian countries and rarely found in Australia but can hitchhike on boats.

"Giant African snails are one of the world's largest and most damaging land snails," he said.

"Strict biosecurity requirements have so far kept these pests out of Australia."