This big: A tourist lies beside the giant squid found washed up on Farewell Spit.

A giant squid nearly four metres long has been found washed up on Farewell Spit.

Paddy Gillooly, of Farewell Spit Tours, said visitors were thrilled to spot the deep-sea creature, which is the biggest invertebrate on Earth.

"We got a real buzz. It's the first one we've seen on the spit in three years," said Mr Gillooly from the Farewell Spit lighthouse this morning.

He said from a distance it looked like a large log, and it was not until he was driving back down the spit from the lighthouse that he noticed what it was. The giant squid was found on the ocean beach at the entrance to the spit.

Golden Bay Conservation Department ranger Mike Ogle said the last giant squid that washed up on the spit had been packed in ice and sent to the Auckland University of Technology for research purposes.

However, this one would be left to let nature take its course.

"The scientist who studied them is quitting his post and we're not aware of any other research projects on giant squid in New Zealand," Mr Ogle said.

Giant squid, which feed on fish, shrimps and other squid, are the favoured diet of the large sperm whales off the Kaikoura coast.