Jewellery was stolen during a burglary in Hanslope on Monday.
Between 4.50pm and 5.10pm the thief got into a house in Newport Road and stole the items.
The offender is white, around 5ft 10ins, of a slim build. He was wearing a long black coat and hat. Witnesses saw a Vauxhall Corsa in the area at the time of the incident
Any witnesses can call police on 101 or Crimestoppers, anonymously, on 0800 555 111.