Masked armed robbers burst into a house in Retford, assaulted the occupant and then tied him up before stealing jewellery.
The incident occurred at around 7.30pm on Thursday February 16 when two masked men burst into the house in the Grove area, one armed with a handgun.
A man was knocked to the floor and tied up whilst a substantial amount of jewellery was stolen.
Officers are appealing to anyone who saw anything suspicious in the area at the time to get in touch by calling 101 quoting incident 818 of 16 February. You can also contact Crimestoppers anonymously on 0800 555 111.