Police believe the woman pictured may have information about the alleged theft of fuel from a petrol station in Corby.
The incident happened at about 12.40am on Monday, May 1, at the Jet garage in Uppingham Road.
A rear seat passenger of a blue Citroen Saxo with a stolen front registration plate got out and refuelled the car, which was then driven off without payment being made.
Officers would like to hear from anybody who thinks they recognise the woman pictured.
Witnesses or anyone with information about this incident can contact police on 101 or Crimestoppers anonymously on 0800 555111.