Seventy-two-year-old Barry Fox is one of hundreds of people saved from scams after bank staff stopped him spending £10,000 on a fictitious Rolls Royce.
The retired lorry driver went into his Barclays branch intending to withdraw the cash to pay for the luxury car he saw on an internet auction site.
Staff were concerned and used a new system to alert police to the case and, within 30 minutes, officers were there.
They made checks and alerted Mr Fox to the fact he was about to be scammed.
This was one of 1,262 calls made by bank staff to police or trading standards under the Banking Protocol system that should see an officer arrive to offer help within an hour.
UK Finance, which represents the major banks, said this had saved potential victims a combined total of £9.1m in its first year of operation. Individuals had been saved between £99 and £212,000 each.
Mr Fox had received some inheritance and had decided to spend it on his dream car.
The seller had told him that they would pick him up from a railway station and then travel to a countryside location to pick up the car. He would pay £10,000 in cash. Bank staff said it "didn't seem right".
The police officers alerted him to the fact that the car was registered hundreds of miles away. The seller on eBay did not match up either, so there was probably no car to buy.
"I might have gone there with £10,000 in my pocket and been knocked over the head with a stick or something," said Mr Fox.
Mr Fox was simply advised not to take out the money in this case. Eventually he bought another Rolls Royce being sold legitimately.
In other cases in the last 12 months, 101 arrests have been made after calls were made by concerned bank staff.
The system has been introduced gradually across the country since May and most police forces are now signed up.
Katy Worobec, from UK Finance, said: "The finance industry is determined to crack down on fraud and is taking action on all fronts. The protocol is an important weapon in our armoury."
One consumer group said that the system should be extended to other types of scam.
Alex Neill, from consumer group Which?, said: "It is right that banks are helping to protect customers from fraudsters by alerting the police to unusual cash withdrawals in branches. But this is a small part of the much wider problem that needs tackling.
"In the first six months of 2017, over £100m was lost to bank transfer scams, so banks must urgently introduce similarly robust measures to deal with online scams, where consumers still remain vulnerable."
Anyone worried about fraud can contact the Citizens Advice consumer helpline on 03454 040506.