Narong Tomee, an employee of Brinks (Thailand), was identified as the main suspect in the theft. The money was stolen from four automatic teller machines in Rayong's Muang and Ban Chang districts in the early morning.
Brinks (Thailand), Bank of Ayudhya's contractor transporting cash to ATM machines, alerted police after the ATM machines at 3am sent alarm signals to the bank headquarters, which at 5am contacted Brinks's Map Ta Phut branch office.
The machines showed no sign of anyone prying them open, and security cameras were blocked at the time by an umbrella.
Police investigations found that four Brinks employees were to put Bt10 million into the four machines at 4pm on Friday.
Brinks reportedly were at time of press unable to locate one of the four, 36-year-old Narong, who had keys and knew passwords to the machines. Police thus strongly suspect that he was involved and might have at least one accomplice, said Rayong deputy chief Colonel Itthidech Charoensahayanont.
Police are watching the borders, he added.
In related news, Bangkok police on Friday night nabbed a former property-developer from the southern province of Chumphon for attempting to steal cash from the ATM machine of Kasikorn Bank's Jarurat branch.
The suspect, Thawatchai Hanthawithong, 49, who allegedly wanted to repay his gambling debts, at 3pm pretended to ask for a Bt4-million loan from the bank and used the opportunity when the officials were busy to hide in the bank's 4th-floor storage area to wait for the bank to close.
When he had cut the security cameras' cords and gone down to the machine on the ground floor, he said, he realised this was a bad idea and tried to get out but failed and was arrested when police arrived.