A West Australian gold company has been fined after 100kg of explosives was stolen from a mine because they were not securely stored. 

Two men and a woman have been convicted over the theft from the Higginsville mine near Norseman, which is operated by Avoca Mining Pty Ltd, a wholly owned subsidiary of Westgold Resources. 

Avoca Mining pleaded guilty in Kalgoorlie Magistrates Court to four charges related to the secure storage of explosives and was fined $20,000.

The Department of Mines and Petroleum said discrepancies between the recorded quantities of explosives and the actual quantities of explosives stored were not investigated by the company.