Residents in Tayside, Angus and Perthshire have been targeted by callers pretending to be from their bank or from other business companies.
The “phishing” fraud ends with victims being encouraged to either transfer their money to another account or provide personal details to the fraudster allowing them to transfer the money.
A 74-year-old woman from Dundee, Tayside, lost £140,000 after being scammed by criminals claiming to be from the fraud department of her bank.
Police say attempts by the bank are under way to retrieve the money.
In another scam, a 75-year-old man from Montrose, Angus, was duped into transferring £74,000 into other accounts. On this occasion the bank managed to retrieve the funds.
And an elderly woman from Kinross, Perthshire, was called by someone claiming to be from BT. She was told her computer had been hacked and her bank details were required which she gave to the caller and lost £5,000.
A spokesman for Police Scotland said: “Police would advise residents to be alert to any phone call they receive from a person claiming to be from a bank, financial institution, business company either asking for money to be transferred or asking for a phone call to be made to the bank. Do not provide any of your details.
“If you do decide to call the bank, where possible call from a different phone line or mobile number. If in doubt, ask the caller to put a stop on your account and attend your branch in person.”