Turkish police detained prominent businessmen on Friday over allegations of financing the group of U.S.-based cleric Fethullah Gulen, a former ally turned foe of President Tayyip Erdogan, the Dogan news agency reported.
It said that the police detained Memduh Boydak, chief executive of furniture-to-cables conglomerate Boydak Holding, as well as the group's chairman Haci Boydak and two board members, and that the police were continuing searches of the company.
Nobody from the company, based in the central Turkish city of Kayseri, was immediately available to comment.
Erdogan has led a crackdown against once influential followers of preacher Gulen, his former ally, after police and prosecutors seen as sympathetic to the cleric opened a corruption investigation into Erdogan's inner circle in 2013.
Memduh Boydak was previously detained in September in an operation targeting Gulen supporters. Around that time, prosecutors sought a jail sentence of up to 34 years for Gulen, who has lived in self-imposed exile in Pennsylvania since 1999.
Police raids have also targeted Gulen-affiliated conglomerates including mining-to-media group Koza Ipek Holding and Kaynak Holding, which is involved in publishing.
Erdogan says Gulen operates a "parallel state structure" in the ranks of the judiciary, police, media and education. Government officials have previously accused Gulen's followers of having ties to the militants of the Kurdistan Workers Party (PKK). Gulen denies such links and himself describes the PKK as a terrorist organisation.