German federal prosecutors on Friday said they had indicted a Turkish national for alleged spying on individuals that he associated with cleric Fethullah Gulen.
The suspect, who is not in jail and was only identified as Mehmet K., in line with German privacy laws, contacted Turkey's police and intelligence service via anonymous letters, prosecutors added.
Gulen built a powerful Islamic movement in Turkey and beyond, but spent his later years in the US mired in accusations of orchestrating an attempted coup against Turkish leader Tayyip Erdogan.
Gulen died last month.