Graeme Sawyer holds the monster cane toad found near Darwin on March 26. Weighing nearly one kilogram, the toad is among the largest specimens ever captured in Australia. ((Frogwatch/Associated Press))

A toad the size of a small dog was captured in Australia, a conservation group said Tuesday.

The monster toad was 40 centimetres long when fully extended and weighed 840 grams, makingit one ofthe largest specimens ofthe invasive species ever found.

"It's huge, to put it mildly," said Frogwatch co-ordinator Graeme Sawyer. "The biggest toads are usually females, but this one was a rampant male … I would hate to meet his big sister."

Frogwatch is an organization dedicated to wiping out the cane toad species, a toxic amphibian that has wreaked havoc on Australia's unique ecosystems.

Cane toads were imported from Hawaii in 1935 in a failed attempt to control beetles in the country's northern sugar cane plantations. The spread of the toads, whose skin is poisonous, has led to sharp declines in the populations of snakes, crocodiles and goanna lizards that eat them.

There are now more than 200 million of the amphibians across northeastern Australia.

Frogwatch captured the toad along with 38 others outside the northern city of Darwin on Monday.

The group kills the toads with carbon dioxide and puts them through a fertilizer process that renders them non-toxic.

With files from the Associated Press