A SNAIL the size of a cricket ball and posing a serious threat to Australia's biosecurity has been destroyed after it was found creeping across a Brisbane container yard.

Staff called the Department of Agriculture, Fisheries and Forestry (DAFF) after finding the large snail crawling across the cement yard.

It was a Giant African Snail.

The exotic pest has an insatiable appetite and is capable of destroying 500 hundred types of plants including vegetable crops, fruit trees and Australia's native eucalypts.

Giant African Snails can live through harsh conditions, growing up to 20 centimetres in length and weighing up to a kilogram.

Acting DAFF regional manager Paul Nixon said on Monday officers found no evidence of other snails, eggs or snail trails when they inspected the container yard.

They will continue precautionary surveillance over the coming week.

"Giant African Snails are one of the world's largest and most damaging land snails," Mr Nixon said in a statement.

"Australia's strict biosecurity requirements and responsive system has so far kept these pests out of Australia and we want to keep it that way."

Meanwhile, a 42-year-old man was on Monday convicted and fined $7000 in the Brisbane Magistrate's Court for illegally importing 48 plant cuttings from France into Australia.

He had asked the seller to make a false declaration on the package when sending it to Australia, DAFF said.

It was found by a detector dog.

The department says plant cuttings pose a significant biosecurity risk and can carry disease as well as harbour exotic pests.

Originally published as Giant snail destroyed in Brisbane