About 1.20am on Tuesday, Ballantynes Showcase Jewellers in lower Thames St was burgled.
Overnight on Monday a white 2002 Subaru Forrester was taken from a Reed St address.
It was reported stolen at 7am on Tuesday and found, damaged, two hours later in nearby Nen St.
Sergeant Blair Wilkinson, of Oamaru, said
police were "investigating possible links between that burglary and the car that was stolen."
The total value of the stolen jewellery was estimated to be in the thousands of dollars.
Store owner Wendy Bradfield said the theft was "devastating" for her and store staff, particularly so close to Christmas.
No arrests have been made and inquiries are continuing.