SYDNEY - A Melbourne man has become an instant multi-millionaire after accidentally winning a lottery twice.

The man, who chose to remain anonymous, from Point Cook in Melbourne's west, accidentally entered Saturday night's Tattslotto draw twice with the same numbers.

When the man's numbers were drawn he won two division one prizes worth 1 million US dollars each.

"At first I thought 'wow I've won (1 million US dollars)' so at first I was lying in bed shaking," the man told News Limited on Tuesday.

"But then after an hour or so I realized I hadn't checked the rest of my tickets so I looked at the net one and to my surprise I found that I'd played the same game twice.

"I wasn't expecting to win once let alone twice."

The man pocketed just under 2 million US dollars tax free from his mistake and plans to buy a home, a Ferrari and take some time off work to travel and see the Seven Wonders of the World.

It is not the first time that a Melburnian has accidentally won a lottery twice.

A woman in her 30s bought two Tattslotto tickets for the same draw in July 2013, winning two division one prizes.

The woman won a total of 638,000 US dollars, half of which she put towards paying off her mortgage.

"I guess it's a good thing we won twice so there's some prize money left over. It will be such a relief to be debt free," she said.