They stopped at a service station, filled up with petrol, and drove off - believing the boy was asleep in the caravan being towed behind their car.

But after 20 minutes on the road last Saturday, they pulled over to check on him and found he had vanished.

Moreover, the couple ended up in the picturesque city of Basel as they took a wrong turn at a junction while driving back to find the kid, Daily Mail reported.

But, in a twist from the story of Hollywood flick "Home Alone" in which actor Macaulay Culkin plays an eight-year-old boy left behind when his family flies to Paris for a holiday, the couple finally made it back to the Pratteln service station two hours later. They found their son being looked after by staff.

A service station worker told Switzerland's Le Matin newspaper: "The child told us that while his parents were filling up with petrol, he got out of the caravan and went to look round the shop.

"But when he came back, his mum and dad had vanished. He was very calm about it all, saying his parents were often 'forgetful' and that he was sure they'd be back to get him soon."