A 27-year-old man got the surprise of his life when he found some $18,752 (15,000 euros) inside a burger meal he ordered from a McDonald's restaurant in Waterloo, Belgium.

Marco Parra-Martinez ordered a take-out burger from a McDrive restaurant.

But he was surprised when he inspected the paper bag containing the meal, to also contain an envelope with the money which is equivalent to over $18,000.

He said, "I hesitated one moment, asking myself if I shouldn't keep the money. But my parents taught me to be honest at all times."

Parra-Martinez decided to return the envelope to the restaurant.

A spokesman for McDonalds said the cash was restaurant earnings that had been accidentally been put inside Parra-Martinez's order. They promised him a reward for his honesty.