The arrests were announced by Phuket Immigration through a statement issued today.
The Immigration Bureau had received a request from the Embassy of Republic of Korea to investigate the four men who were reported as staying in Phuket and working illegally, the statement explained.
Phuket Immigration officers tracked the men to a house at the Phuket Villa Kathu housing estate.
Officers, armed with a warrant, raided the house at about 4:30pm last Tuesday (Dec 29) and found the men working online trading cryptocurrencies.
The four Korean men were named as Kang Mingu, Chul Jae Jung, Min Joo Won and Kim Hyun Su.
Kang Mingu was wanted on an Interpol for distributing child pornography, the Phuket Immigration statement noted.
Officers also found a loan agreement document at the scene, providing evidence that the men had operated a loan operation and charged rates of interest exceeding the maximum legal rate, the statement added.
Also seized as evidence were six laptop computers, 10 computer monitors, electronic equipment, bankbooks and the loan contract document, Phuket Immigration also noted in their report.
Officers are now investigating further and gathering more evidence, including questioning witnesses, in order to proceed with charges against the four men, the Phuket Immigration said.
All four will be charged with working illegally in the country, and Kang Mingu will face an additional charge of entering and staying in the country illegally, the report noted.
Kang had overstayed his permit to stay by more than 253 days, Phuket Immigration explained.