The Cyber Crime Investigation Bureau (CCIB) is warning people not to fall for calls by scammers pretending to be staff from the Department of Internal Trade after one such crook allegedly took 16 million baht from a man's bank account.

A man named only as "Mr Wachara", 40, a businessman in Chon Buri, said on Monday that a scammer had called him on Friday, claiming to be a Department of Internal Trade official.

He was told to open a link sent to his Line mobile app and fill out the form with his personal information. After submitting the form online, Mr Wachara found that there had been nine withdrawals from his savings account worth 16 million baht.

According to an investigation, the money was withdrawn from a Siam Commercial Bank account and sent to 20 accounts and then eventually transferred into cryptocurrency, police said.

A CCIB spokesman said that there has been an increasing number of scams recently.

Many callers claimed they were Commerce Ministry officials and asked victims to install an app on their mobiles to update their company and personal information.

After the victims completed the process, the app, which was malware, shared the information and allowed criminals to access accounts on banking apps and transfer money into proxy accounts.

The CCIB said it was important that people avoid opening suspicious links sent from unknown phone numbers.