Senior Constable Tom Taylor, of Balclutha, said between 30 and 40 digger teeth, also called digger tips, were taken from beside a container at the Kai Point Coal site between 6pm on November 6 and 3pm on November 7.
The missing teeth have a combined value of about $3700, and some may still be painted blue like the one pictured.
Snr Const Taylor said police believed offenders might have used a four-wheel motorbike to steal the digger teeth, moving large rocks to gain access to the mine site. He asked anyone who saw anything suspicious in that area on November 6 or 7 to contact the Balclutha police on (03) 418-0203 or Crimestoppers on 0800 555-111.