Police have now issued an appeal to try to trace Mr Kupiec as concerns are growing for his welfare.
He was last seen at around 1.30pm on Wednesday, January 5, wearing a large white coat and blue jeans/trousers.
He is Polish, white, 5ft 7in tall, heavy built and has short brown hair.
Anyone who has seen Mr Kupiec, or anyone who has information on his whereabouts should contact Police Scotland on 101 quoting incident number 0075 of January 6.
Police Scotland has Missing Person Coordinators (MPCs) in every local division in the country.
MPCs support and oversee all missing person investigations.
Police Scotland says MPCs ensure missing persons have the “correct level of support” once they are found.
There are currently two other people missing in Edinburgh who police are looking to trace, Alice Byrne, 28 and Dean Conner, 37.