A passenger may bitterly regret visiting McDonald's before embarking on his journey to Australia from Bali, Indonesia.

According to the Australian Department of Agriculture, a search dog at Darwin Airport found a burger with beef and egg, a ham croissant and a McMuffin in the man's backpack.

Minister Murray Watt said it was a biosecurity breach.

"This will be the most expensive McDonald's meal the passenger has ever had," Watt said.

But he has no sympathy for the man, who has to pay double what his plane ticket cost for the violation: $2,664.

Watt praised Zinta, a black Labrador who recently joined the airport.

The leftovers were checked for foot-and-mouth disease virus and then destroyed.

Biosecurity is important, Watt said.

"It protects our farmers and secures jobs." And that's also because there is no foot-and-mouth disease in Australia.