The theft took place outside a supermarket on Harborough Road on April 10 between 12.40pm and 12.50pm.
A woman at a cashpoint was distracted by two men who them stole money from her.
Northamptonshire Police have now released images of two men they believe could have information about the theft.
The men in the images or anyone who recognises them should contact Northamptonshire Police on 101. Information can also be shared via Crimestoppers in confidence on 0800 555111.