Cha Du-ri secures Germany return
The German-born South Korea international arrived at Parkhead two years ago, after catching the eye of Neil Lennon during the 2010 World Cup.
Celtic snapped up the 31-year-old from Freiburg and Cha tasted success during his two years at the club, winning the Scottish Cup and Scottish Premier League title during his time in Scotland.
However, the Hoops have now confirmed his exit, with the defender opting to return to the country of his birth.
"Cha Du-ri has signed for Fortuna Dusseldorf after spending nigh on two years with the Hoops," read a statement on Celtic's official website.
"The German-born South Korean internationalist returns to football in the land of his birth after making 44 appearances for Celtic, during which he scored twice.
"Everyone at the club would like to wish Cha every success in his future career."