Turkey's President Recep Tayyip Erdogan has branded the alleged racism which caused Mesut Ozil to retire from international duty with Germany as "completely unacceptable".
Ozil announced his retirement from international football on Sunday - accusing some German FA officials of racism - following a storm of abuse after he was pictured with Erdogan ahead of the World Cup.
The Arsenal midfielder, who is a Muslim and has Turkish heritage, also revealed he and his family had received hate mail, threatening phone calls and social media abuse following Germany's poor World Cup campaign.
The German FA (DFB) rejected Ozil's accusations and called out the 2014 World Cup winner for his failure to provide answers regarding the controversial photograph of himself and Germany team-mate Ilkay Gundogan with Erdogan - who has been accused of abusing human rights laws and restricting the freedom of the press.
Now Erdogan has come to Ozil's defence.
Quoted in Turkish newspaper Sabah, Erdogan said: "Such a racist approach, due to his religion, towards a young person who gave everything for the German national team, contributing to its successes, was completely unacceptable."
The president of the Turkish Football Federation, Yildirim Demiroren, has also spoken out in support of Ozil.
Demiroren told the federation's website, tff.org: "I condemn the treatment, the threats and the humiliating messages that have been sent to him because of his origins.
"Every player should be protected against messages of humiliation, discrimination and hate.
"All members of the international football community should unite in destroying racism and intolerance - it must continue to fight tirelessly."
Ozil's treatment and subsequent decision to retire has divided opinion in Germany.
Bayern Munich president Uli Hoeness slammed the decision, describing Ozil as "weak", adding the 29-year-old has "been playing dirt for years".
That prompted Ozil's agent, Dr Erkut Sogut, to issue a statement saying Hoeness' comments "had nothing to do with football" were intended "to divert attention away from the real issue, the issue of racism and discrimination in Germany".