Police have released CCTV images of people they want to question in relation to letters being stolen from a post box and used to open bank accounts in the victims' names.
Criminals then withdrew money from accounts's automatic overdrafts from cashpoints in Chingford and used to buy expensive items, including a Rolex watch.
The theft of post took place in Cuffley in Hertfordshire between November 11 and 15, 2013.
The fraudulent transactions occurred on November 13 and 15, 2013.
A police spokeswoman said: “Police believe that the thieves have committing these offences nationally and could frequent Bluewater Shopping Centre, Chingford and Enfield.
“Officers would like to speak with men pictured.
“It may be that they witnessed the crimes or can offer assistance in the investigation.”
Anyone with information should contact Hertfordshire Police's non-emergency number 101 quoting crime reference number B2/13/3946. Alternatively call Crimestoppers, the independent charity, anonymously on 0800 555 111.