Chinese police have reportedly arrested three suspected hacked alleged to have stolen bitcoins and other cryptocurrencies worth $87 million.

According to a report in Xinhua, China’s state-owned press agency, police in the city of Xi’an in northern China first began investigating a complaint by a victim who alleged hackers had compromised his computer to steal 100 million yuan (approx. $15 million) in cryptocurrencies that included bitcoin, ethereum, and others.

A task force was set up and a preliminary investigation revealed that hackers had used remote hijacking techniques to gain access and control of cryptocurrency accounts belonging to the victim – only identified as Zhang – with nearly no footprints of the crime.

The investigation progressed and three months later, the task force was able to spot a suspect, named Zhou, with the help of ‘well-known’ internet companies in China. Authorities kept their distance and began tracking Zhou’s activities for a further two months. Before long, police identified two other accomplices by snooping in on Zhou’s communication.

The three suspects are altogether alleged to have stolen an initially estimated 600 million yuan (approx.$87 million) by targeting corporate and personal network systems through a number of illegal means including cyber-intrusion and hacking, police claim.

Zhou, who belongs to the central Chinese province of Hunan, is currently in custody along with his two alleged accomplices. Despite the eye-watering value of stolen cryptocurrencies involved in the alleged theft, police across three provinces continue to work together in a still-ongoing investigation. It remains to be seen if the value of the stolen cryptocurrencies exceeds the police’s current initial estimate.

While financial authorities in China have effectively banned trading of cryptocurrencies following crippling regulations in 2017, Chinese police have also been quick to crack down on crypto-related criminal activity including crypto jacking – a technique wherein malware is deployed on a victim’s computer to surreptitiously mine cryptocurrency, and electricity theft for crypto mining operations.

In July, a joint law enforcement effort between Chinese authorities led to the arrests of developers of malware that amassed $2 million in cryptocurrency by allegedly mining them across a million infected computers in the country.

During the last few months, police in the city of Tianjin and the Anhui province have also arrested cryptocurrency miners for stealing electricity to power their mining rigs, equipment which has also been seized by the authorities.