The elderly victim from Airdrie was left traumatised after two men posing as police officers entered his home.
The 65-year-old let the pair – dressed in suits and wearing earpieces – into his home in Kennedy Drive at around 6pm last Monday.
The thieves told them him they were looking for stolen goods and showed him fake warrant cards.
Once inside, one of them held the victim in his bedroom while the other stole gold jewellery, a purse and medals before the pair fled.
An image of a man police want to speak to has now been released.
Detective Chief Inspector Pat Campbell of Motherwell Police Office said: "This was a brazen and despicable attack which has left an elderly man very traumatised.
"We are doing everything in our power to catch the men."
The first man is described as being about 5ft 4in tall and wearing glasses.
The second man is about 6ft tall.
Detectives are keen to speak to anyone who recognises the man in the image or who has any other information in connection with the raid.
Alternatively, call Crimestoppers on 0800 555 111 where information can be given anonymously.