This article originally appeared on ABACUS When police arrived on the scene in the northern Chinese city of Daqing, they found what seemed like it could have been ripped from the pages of a thriller novel: Two mysterious grave mounds were lying in the field. But this wasn't the site of a grim murder. The mounds were actually hiding a bitcoin mining operation. After receiving a tip from a local oil field company about suspicious power losses, Daqing police decided to inspect the area last Tuesday, Chinese state media Beijing News reported on Sunday. Police found an entrance near the mound and, after some digging, confirmed that it was a bitcoin mining rig that was illegally stealing electricity. According to media reports, this isn’t an isolated incident. That very same week, in the same county in Heilongjiang province, police found that one imaginative bitcoin miner hid 54 mining rigs deep under a dog kennel . These incidents may have been spurred by the recent rise in the price of bitcoin. Although cryptocurrency trading is illegal in China, mining it isn’t. The country has been a haven for mining farms in the past thanks to its cheap electricity.