Four men wearing grey face masks broke into a house in Bletchley before stealing Asian gold and cash.
At 7.30pm on February 20 the men broke into a house in Normandy Way, where they threatened the owners and stole the items. No one was injured during the incident.
Three of the men were tall, and one was shorter. All were aged in their mid thirties wearing grey masks, which looked similar to surgical masks, covering the lower half of their faces. One was wearing a yellow and black cap.
Detective Sergeant Jason Simpson, from Milton Keynes Force CID, said: “I would like to speak to anyone who saw people matching these descriptions acting suspiciously in the area at the time of the incident.
“A silver car may be linked to this offence so please speak to police if you saw a vehicle such as this in the area at the time.”
Any witnesses can call police on 101 or Crimestoppers, anonymously, on 0800 555 111.