Detectives later found the elderly man’s payments had been spent in a range of places including restaurants and luxury retailers, where jewellery and clothes were purchased.
Det Supt Andy Buckthorpe, of Greater Manchester Police, said the scale of the exploitation was “truly alarming”.
“Thanks to the diligence of the bank and their knowledge that something wasn’t right, we were able to immediately respond and make a positive arrest, but also safeguard the victim to ensure he is now protected,” he said.
“Fraud has a real lasting impact on victims and their families and cannot be underestimated.”
The force said it would continue to work with the region’s banks so this sort of suspicious activity can be uncovered at an early stage.