The 39-year-old was detained in Bangkok on Feb. 26 following a joint operation with Singaporean authorities, Thai police said on Feb. 27.
The suspect, identified by police as Chia, is accused of hacking into dozens of companies, stealing sensitive data and selling it on the dark web.
His arrest followed an extortion complaint from a Thai company which reported receiving threats via the X account "@0mid16b", demanding payment in exchange for withholding stolen customer data.
Chia has been charged with extortion, unauthorized access to computer systems, and illegal stay in Thailand, officials said.