Police in the Chinese city of XI’an has arrested three hackers suspected of stealing more than 600 million yuan ($87 million) in the cryptocurrency.

Law enforcement authorities reported that they had launched an investigation on March 30 after receiving a complaint of a local resident, who said that hackers broke into his computer and stole more than 100 million yuan in bitcoin and ether.

The initial investigation revealed that the suspects had an advanced knowledge in hacking computer systems, thanks to which they managed to hide for a long time. The situation was also complicated by the anonymity, which to some extent gives its users the cryptocurrency.

According to investigators, the hackers shared the stolen cryptocurrency for small amounts and carried out multiple transactions to cover their tracks. Police analyzed some 30,000 recordings and took the help of local Internet providers. After three months of investigation, they managed to get on the first suspect named Zhou, who lived in the Central province of Hunan. Another two months took law enforcement officers to identify his accomplices: Tsui Beijing and Zhang from Jilin province.

The police reported that all the detainees are experienced hackers, in the past worked for leading Internet companies. The group was able to take possession of 600 million yuan in the cryptocurrency, hacking computers of individuals and organizations. Part of the stolen has been withdrawn in Fiat for a subsequent purchase of luxury villas, cars and products in the field of wealth management.

In may it became known that 98 people in China have been accused of organizing a crypto-pyramid OneCoin and appropriation of $2 billion, owned by local investors.