"We have detained one person," deputy national police chief General Chaktip Chaijinda told reporters but police would not confirm the nationality of the detained person who local media said was Turkish.
"We have found components of bomb-making materials in his apartment and I am confident that he is likely involved with the bomb attack," he said.
National police spokesman Prawut Thavornsiri said in a televised statement that police had also found detonators, metal pipe with lids at the suspect's apartment during the raid this afternoon.
The materials included 0.5mm-diameter ball bearings that were similar to the type used with the bombs that exploded at the shrine and at the Sathorn Bridge a day later.
More From This Section
Colonel Banphot Phunphien, spokesman of the Internal Security Operations Command (ISOC), was quoted by a media report as saying that the arrested man "is a Turkish national".
"He carries many passports. It's unusual how he carries so many passports," Banphot added.
Thai police had released a sketch of a young bespectacled "foreign man" as prime suspect in the August 17 bombing who was captured on CCTV wearing a yellow T-shirt and placing a backpack on a bench inside the Erawan Brahma temple's compound and walking out just before the explosions.
He is believed to be part of an over 10-member network and authorities had announced a reward of 1 million baht for information leading to his arrest.
However while he was speaking, photo passport page of a Turkish national named Adem Karadag and pictures of a number of Turkish passports wrapped in rubber bands were broadcast.
Prawut said the investigators would question him to find out his links to the two blasts.
Twenty people were killed and 127 others injured in the bombing which took place during the evening rush hour at the popular tourist destination. The second blast on August 18 near Sathorn canal did not cause any injuries.