The Polish athlete earned bronze at light middleweight in the Japanese capital in 1964. 

Boxing is one of Poland's most successful Olympic sports, with Grzesiak one of 43 Polish medallists in the history of the Games. 

Grzesiak also represented Poland on the international stage at the 1955 European Amateur Boxing Championships in Berlin.

He had a total of 198 fights in his career, boasting a record of 157 wins, 14 draws and 27 defeats.

The reason for his death is currently unknown. 

Polish Olympic Committee President Andrzej Kraśnicki expressed his "sincerest condolences" to the family and friends of Grzesiak.