Mesut Ozil's shock retirement from international football caught Germany head coach Joachim Loew by surprise, it emerged on Tuesday.

Loew was on holiday in Sardinia when news of Ozil's retirement broke on Sunday and he only found out when the Arsenal midfielder posted statements on Twitter and Instagram.

"Neither the national coach nor I were informed in advance," Loew's agent Harun Arslan confirmed to German daily Bild.

Ozil, 29, dropped a bombshell by announcing his retirement from Germany duty and accused the president of the German FA, Reinhard Grindel, of racism.

"In the eyes of Grindel and his supporters, I am German when we win, but I am an immigrant when we lose," Ozil wrote in his lengthy farewell statement.

Ozil, a 2014 World Cup winner was born in Gelsenkirchen but has strong Turkish roots.

The German Football Association (DFB) on Monday refuted Ozil's allegations of racism, but the fiasco has damaged the governing body's reputation in football-mad Germany.

A survey of 5,000 Germans by t-online.de showed 49.7 percent think Grindel should resign over the saga.

Ozil says he is quitting over the furor caused by his meeting with Turkish president Recep Tayyip Erdogan on the eve of the World Cup as Grindel failed to back him amidst the criticism.

When Germany crashed out of the World Cup in Russia after the knock-out stage, Ozil was made a scapegoat by some pundits in a group of senior players who failed to perform.

He was dropped after the shock 1-0 defeat to Mexico, sitting out the last-gasp 2-1 win over Sweden, but was one of several stars who played poorly in the 2-0 defeat to South Korea which confirmed Germany's early World Cup exit.