Canadian police are seeking information on individuals alleged to be involved in defrauding Bitcoin (BTC) ATMs (BTMs), according to an announcement published by the Toronto Police Service on March 13.

The Calgary Police Service (CPS) Cybercrime Team has asked the public to assist in the identification of four individuals allegedly involved in multiple fraudulent transactions made within the country and targeting one Canadian Bitcoin firm. The CPS initially received the information in October 2018.

The press release states that in September of last year, the suspects allegedly made 112 fraudulent transactions at BTMs in seven Canadian cities, including Calgary, Toronto, Montreal, Ottawa, Hamilton, Winnipeg, and Sherwood Park. The CPS believes that the suspects made “double-spend” attacks.

In such attacks, the suspect allegedly withdrew money from a kiosk and subsequently cancelled their transaction remotely before the BTM operator could process the withdrawal. The fraud reportedly resulted in CA$195,000 ($146,666) in losses to the company.

Recent research published by crypto analytics company CipherTrace in January revealed that about $1.7 billion in cryptocurrency had been obtained via illicit means in 2018. Of that $1.7 billion, over $950 million was stolen from crypto exchanges, representing a 3.6 times increase over 2017. In 2018, at least $725 million was lost to scams such as ponzi schemes, exit schemes and fraudulent initial coin offerings.

At the same time, analytics company Chainalysis reported that cryptocurrency-related crime has decreased over the past few years, only accounting for 1 percent of all Bitcoin transactions in 2018. Chainalysis also made a prediction of criminal trends in the space in 2019, outlining increased usage of decentralized platforms and efforts to move and launder money around the world through cryptocurrencies.