A Sydney dad has scored two multimillion-dollar first division Lotto prizes after a happy accident.

The Parramatta man won two of the six division one prizes in Monday night’s draw after accidentally marking two games with the same numbers.

The single division one prize was $666,666.67, so the lucky father takes home a total prize of $1,333,333.34.

“It wasn’t deliberate that I had two rows of the same numbers. It was just that I had to mark another line on the ticket – so it’s a very happy accident,” he told lottery officials on Tuesday.

The double division-one winner, who wanted to remain anonymous, said he was in a state of shock at his good fortune.

“You have no idea how this has helped my family,” he said.

“It’s already been spent … but all wisely, I can assure you.

“It’s so much appreciated.”

He bought his winning ticket at a Parramatta newsagency. Owner William Ho said it was the first division one prize he had sold in 15 years.

“I was very happy this morning when I saw we had sold not one but two division one wins,” he said.

There was also a third first division one winner from Monday night’s draw in NSW. The other winners came from Victoria, South Australia and Queensland.