A bike was stolen from outside Lidl in Gainsborough Road, Corby, on Monday, August 13.
Sometime between 11.30am and midday, an offender took the grey and black Raleigh Traxx from outside the shop.
The offender was white, of scruffy appearance and described as old.
Officers would like to speak to anyone who witnessed this incident or has any information about it.
A police spokesman said: “The bike has great sentimental value to the owner who would like it back, no matter what condition it is in.”
Witnesses to this incident, or anyone with information about it, can call Northamptonshire Police on 101 or information can be given anonymously to Crimestoppers on 0800 555111.