Thieves stole cash from a house on Park Street in the early hours of Friday morning.
It happened between 1am and 6am when burglars broke in through a window while the occupants were in bed.
Police have linked the incident to another burglary on Lower Gladstone Street, in Heanor, which took place between 10.25pm on Thursday and 6.30am on Friday.
A search was conducted but nothing was taken.
Anyone with information is asked to call polilce on 101.