Australian athlete John van Wisse has smashed the world record in the gruelling 483-kilometre Arch to Arc ultra-triathlon from London to Paris.

The 41-year-old Melburnian cut 12 hours and 12 minutes off the previous record when he crossed the finish line in Paris at 6.45am Friday, Melbourne time, in a time of 61 hours and 27 minutes.

The Enduroman Arch to Arc, from from London's Marble Arch to the Arc de Triomphe in Paris, is one of the world's toughest sporting events and van Wisse is only the 14th person to complete it.

Van Wisse told radio station 3AW just after finishing the race that he was ecstatic with the result.

"I've done some brutal training and it's been a year's build-up and I'm just absolutely stoked," he said.