When the man went to Alexandra Westpac Bank to access the funds, staff realised that something was wrong and that he was possibly about to be scammed, so accompanied him to the police station.
Police then went to the elderly man's address and waited for the call.
"The caller had an accent and stated their representative would not come around until the man had given them the code numbers for the vouchers first," Kerrisk said.
"The male was very insistent and swore at the man. He hung up and another man with an accent then called again and attempted to get the elderly gentleman to give him the voucher code numbers - he too was very aggressive."
On the final call police answered the phone and identified themselves but the call went dead straight away.
Police believe the callers were from overseas and only required the voucher numbers to gain access to the funds.
Kerrisk said if any member of the public believes they might be on the receiving end of one of these calls, they should do the following:
"Hang up immediately. If it doesn't seem right, be cautious, double-check details first."
He advises people to look after their personal details in the same way they would a wallet and other possessions.
"Your personal details are very valuable to scammers, they will use your details to take out loans or run up debts if they can.
"Be aware of common scams: for example, banks, Immigration New Zealand or Inland Revenue never email, call or text customers to ask for money to be sent using money transfer services.
"If you receive a request like that, it's a scam."
Further advice is not to trust anyone who calls you and asks for your financial related information, such as your account details and password, or anyone that offers you a reward that you have to pay for first.
- If you have been targeted by a scam, report it immediately by visiting the Consumer Protection's Scamwatch website.