Premier League stars Mesut Ozil and Ilkay Gundogan have been criticised for posing in photographs with the Turkish President Recep Tayyip Erdogan.
Both players are of Turkish descent and play for the German national football team.
Germany and Turkey are competing to host the European Championships in 2024 with a decision expected to be made by Uefa in September.
The German football federation (DFB) has raised questions about Turkey’s credentials under Erdogan - who is facing an upcoming general election in June.
DFB president Reinhard Grindel said "The DFB of course respects the special situation for our players with migrant backgrounds, but football and the DFB stands for values that Mr. Erdogan does not sufficiently respect. Therefore, it is not a good thing that our internationals have let themselves be exploited for his election campaign stunt. It certainly hasn’t helped the DFB’s integration efforts.”
While DFB team coordinator Oliver Bierhoff said:“I still have absolutely no doubts about Mesut and Ilkay’s commitment to playing for the Germany national team and how much they identify with our values. They were unaware of the symbolism of these pictures, but we cannot endorse it, and we will discuss the matter with the players.”
The president of the Turkish Football Federation has responded to the criticism.
"I don't think it's fair that we get them involved in our campaign," Servet Yardimci said.
"Mr Erdogan used to be an active football player so he loves having meetings with Turkish football players. He does also meet foreign players in Turkey whenever he has got the time."
"That's one of the reasons why he met them yesterday.To find out how many goals they scored, how they are doing. Football chatting."
"We don't think human rights will be a problem from Uefa's point of view because Turkey is fully compliant”.
"Obviously the Turkish government is doing whatever is necessary to protect its unity and its system in place. There may be areas of shutting down social media and so forth but I don't think this is in breach of Turkey's compliance or commitment to the human rights treaties."
A state of emergency declared by Erdogan after the failed military coup in 2016 was used to crack down on the alleged coup plotters. The emergency powers have been used to arrest other government opponents and forced the closure of media and non-governmental organisations for links to extremist groups.
The detention of German citizens by Turkey has contributed to the troubled ties between Chancellor Angela Merkel and Erdogan.
Gundogan, who won the Premier League title with Manchester City, has said in a statement: "It was not our intention to make a political statement with this picture, still less to take part in election campaigning.
"As German national players, we stand by the values of the DFB and are aware of our responsibility."
"Football is our life and not politics."