A protest banner shows President Recep Tayyip Erdogan (centre) and cleric Fethullah Gulen (R) at a demonstration on December 30, 2013 in Istanbul
Istanbul (AFP) - Turkish police on Sunday detained a brother of the US-based preacher Fethullah Gulen who is accused of masterminding the failed July coup aimed at ousting President Recep Tayyip Erdogan, the first time one of his siblings has been apprehended.
Kutbettin Gulen was detained by police acting on a tip-off at the home of a relative in the Gaziemir district of the western Izmir province, the state-run Anadolu news agency said.
He is accused of "membership of an armed terror group", Anadolu said, without giving further details.
Kutbettin Gulen was being questioned by anti-terror police and Anadolu said books belonging to Fethullah Gulen himself were confiscated in the police raid.
Fethullah Gulen, a former Erdogan ally who has lived in self-imposed exile in the United States since 1999, is accused by Turkey of orchestrating the July 15 coup plot.
Gulen denies the claims and his supporters ridicule the description of his group by the Turkish authorities as the Fethullah Terror Organisation (FETO), saying he merely runs a peaceful organisation called Hizmet (Service).
According to previous Turkish media reports, Gulen has three living brothers, Mesih, Salih and Kutbettin, as well as two who are dead, Seyfullah and Hasbi. He also has two sisters, Nurhayat and Fazilet. Their current whereabouts are not known.
In July, the authorities arrested Gulen's nephew Muhammet Sait Gulen in the eastern city of Erzurum, long seen as one of the hubs for his supporters.
Another nephew, Ahmet Ramiz Gulen, was arrested in August in the southeastern city of Gaziantep.
But this is believed to be the first time a brother has been detained following the coup bid.
- 'Uproot the traitors' -
Some 32,000 people have been arrested since the attempted putsch over their alleged links to Gulen, in a relentless crackdown that has caused international concern.
Those arrested include top former generals accused of organising the coup but also people from every sector of life ranging from sweet pastry magnates to journalists to former footballers.
Speaking to a meeting of youth activists in Ankara, Prime Minister Binali Yildirim vowed the crackdown would continue until Gulen's influence was eradicated from every aspect of life in Turkey.
"Now it's time to clear them out of all the structures. We will uproot these traitors from anywhere, from within the state, business, politics," he said.
"No-one should play the victim here," he said, vowing however to "act not with a feeling of revenge but with justice".
Turkish officials have scoffed at any suggestion there could be second coup bid but Yildirim warned there "can be no complacency and we will be ready for anything day or night".
In a televised speech to supporters in the town of Kazan outside Ankara, Erdogan vowed to apprehend the remaining alleged coup plotters still at large.
"'We are coming to your lairs!' we said and we came to their lairs. Now they are fleeing, looking for a hole to hide in," he said.
"Wherever they go, we will chase them, We will... bring them to account."
Turkey has asked the US authorities to extradite Gulen to face justice back home and expressed impatience with the slowness of the procedure.
But Washington has insisted the full judicial process should be observed.
It is still not clear when the first trials will start but Justice Minister Bekir Bozdag has said they will take place across the country, with special court facilities needing to be set up in some places.