A German state minister on Thursday called on Bundesliga club Darmstadt to take action against their player Aenis Ben-Hatira in connection with his engagement at an Islamic organisation.
Peter Beuth, Interior Minister in the state of Hesse where Darmstadt is located, told hr-iNFO radio that Ben-Hatira's support of the "Ansaar International" group violated Darmstadt's statutes which do not permit anti-constitutional acts.
"I expect the statutes to be applied in this case," Beuth said.
Regional intelligence offices have said the organisation is closely linked to the Salafist movement in Germany.
Beuth said Salafism - an ultra-conservative strand of Sunni Islam which supports the implementation of Islamic law, or sharia - rejects the nation's constitutional values.
The Germany-born Tunisia international Ben-Hatira has confirmed the engagement but insisted that "Ansaar International" has nothing to do with extremist Islam which he opposes.
More than 8,500 people are considered part of the Salafist movement in Germany. Some groups are suspected of recruiting Muslims on behalf of the Islamic State group.
