Turkish President Recep Tayyip Erdogan said on Saturday he is closely following an inquiry into a US-based Islamic preacher and media outlets close to him and dismissed criticism that the case is politically motivated.Erdogan spoke a day after an Istanbul court ordered the arrest of Fethullah Gulen, whom Erdogan has accused of leading a terrorist plot to seize power and whose supporters the president has purged from the judiciary and police.The arrest warrant for Gulen, who lives in self-imposed exile in the US state of Pennsylvania, could test relations with Washington and raise questions about judicial independence in Turkey. A Turkish prosecutor has accused him of leading an armed terrorist group"I am closely following the legal process," Erdogan said in a speech broadcast live by NTV channel. "Everything is working according to the law. No one is being lynched."Once close allies, the two men's relationship ruptured in December 2013 when a corruption investigation by police seen as close to the cleric's Hizmet (Service) movement implicated Erdogan and some of his family members and cabinet ministers.The president has described the corruption case as a coup plot. The graft probe has since been formally dropped.