Karadag was arrested on August 29 in a room in the Pool Anant Apartment in Bangkok's Nong Chok district where authorities discovered bomb-making materials, the Bangkok Post reported.
But according to the latest evidence and investigation, authorities suspect he might be the perpetrator of the Erawan shrine blast on August 17 which killed 20 people and injured 130 others, security sources said.
Some of the evidence comes from CCTV footage shot in Lumpini Park showing a yellow-shirted man suspected of planting the bomb at the shrine going into a toilet in the park, where he changed his shirt to a grey one.
The man seen in the footage leaving the toilet resembles Karadag, the sources said, adding after leaving the park, he took a public bus to the apartment in Nong Chok.
Karadag has a long scar on his arm, while the yellow-shirted suspect seen in the footage had straps around both of his arms, the sources added.
The new evidence was shown to Karadag and he allegedly admitted to being the yellow-shirted suspect who disguised himself, wearing a wig and glasses.
Investigations are ongoing to verify if he is the culprit.
Meanwhile, Malaysian police yesterday announced that they arrested eight people suspected to be linked to the bombing.
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