A Syrian refugee has been hailed a "hero" in Germany after handing in 50,000 euros and bank books he discovered hidden inside a second-hand wardrobe.

The 25-year-old man, who Germany's Bild newspaper identified as Muhannad M, fled to the country from Homs last year and had been trying to cheaply furnish his new home in Minden, in the country's north.

He found the stash of cash and five bank books inside a hidden compartment built underneath one of the shelves of the cupboard.

Muhannad points to the place where he found the cash. ( Supplied: Minden Police )

Muhannad promptly reported the find to his local immigration office, who then passed the information on to police, but not before first having to google whether the cash was real.

"They were all new 500-euro bills. I thought it was counterfeit money," he told Bild.

In a statement, Minden police hailed Muhannad a "hero" and thanked him for his honesty.

"This young man has behaved in an exemplary way and deserves great credit," it said.

Muhannad's family still lives in Syria and he told Bild he could have used the money to help his two younger brothers flee the war-torn country.

But Muhannad said it had never been an option to pocket the cash.

"I am Muslim. This money I could not keep to myself," he told Bild.

"Allah would never allow it, to finance your own interests with someone else's property."

Police are now trying to determine the rightful owner of the cash.

According to Bild, Muhannad will be entitled to a 4,500-euro reward, or 3 per cent of his find.