Three men have been detained on suspicion of hacking into computers and stealing about 600 million yuan (US$87 million) worth of virtual currency, police in northwest China said.
Officers in Xian said the case was the highest value cryptocurrency criminal investigation in the country so far, Huashang News reported on Saturday.
The police started investigating the case in March when a man from the city complained his computer had been hacked and 100 million yuan in bitcoin and ethereum had been stolen.
“Our bureau has not dealt with this kind of case before,” one officer was quoted as saying. “It’s the first virtual currency-related case in Shaanxi.”
The officer also said the complex technology involved made it easy for expert hackers to cover their tracks.
The three suspects were described having studied hacking technology since they were aged around 12 and 13 and had gone on to work at top internet firms.
Police said the hackers had split the income from selling the stolen virtual currency into smaller units and had then carried out multiple transactions to cover their traces.
Police analysed 30,000 pieces of information and called on the help of domestic internet companies before identifying the first suspect, a man named Zhou from Hunan province.
It took police another two months before they found the two other suspects: a man surnamed Cui in Beijing and a man named Zhang in Jilin province.
Police watched them around the clock before detaining all three in coordinated raids on Wednesday. The case is still under investigation.