A 23-year-old British backpacker died after being bitten by a sea snake while working on a fishing trawler near a remote island off northern Australia.

In a rare accident that marked the first known death from a sea snake in Australia, the man was bitten as he hauled up a net on a boat near Groote Eyland, a large island off the coast of the Northern Territory.

Authorities said ships and a rescue helicopter rushed to the trawler to provide medical supplies but were unable to assist.

“They went out to the trawler but unfortunately by the time they got out there he had passed away,” said Craig Garraway, from St John Ambulance.

Northern Territory police said they had notified the British High Commission. The man’s identity has not yet been revealed.

“Police will continue with their inquiries and a post mortem will be conducted,” a police spokeswoman said.

An antivenom exists for sea snake bites, but it is not known whether any was on board the trawler.

Australia has 21 of the world's 25 most lethal snakes, including the entire top ten, according to a study in 1979.

But the Marine Education Society of Australia said no deaths have previously been recorded from sea snake bites in Australian waters. It said about 32 of the 60 known species of sea snake are in Australia.