A collection of rare coins and banknotes were among the items stolen in a burglary in the early hours of Saturday morning.
The offenders smashed a window to get into the house, in Sudbury Close, Chesterfield, between 3am and about 3.30am.
Once inside, the suspect woke the 71-year-old homeowner up and asked him for valuables.
The offender stole three maroon-coloured albums containing rare and historical coins and banknotes.
Among the collection were three shillings from Queen Victoria’s reign, three £20 notes with chief cashier signatures on them, a £50 note and a Scottish £50 note.
Officers want to speak to anyone who has been offered the collection for sale, or has seen someone with similar items since the incident.
The offender was white, aged in his late 20s or early 30s, and wearing grey trousers, a grey jumper and a grey beanie hat.
Officers also want to speak to anyone who spotted someone matching that description in the early hours of Saturday morning, or anyone living in the area who believes they could have CCTV footage of the suspect.
Witnesses or anyone who can help should call police on 101, quoting reference 19000226414.