Randall Crater, the founder of the My Big Coin cryptocurrency and payment service, was sentenced to more than eight years in jail for marketing and selling a fraudulent virtual currency and operating an unlicensed virtual currency exchange, the U.S. Attorney's Office said on Wednesday.

A federal court in Boston ruled the 52-year-old Crater will also have to serve three years of supervised release. He was convicted in July of wire fraud and money laundering after being charged in 2018 by the Commodity Futures Trading Commission.

Crater’s firm offered virtual payment services through a fraudulent digital currency known as “My Big Coins,” which were marketed to investors between 2014 and 2017, defrauding them of more than $6 million. He and his associates claimed the coins were a functioning cryptocurrency backed by $300 million in gold, oil and other assets. They also falsely told investors the company had a partnership with Mastercard and that My Big Coins could be easily exchanged for fiat currency or other virtual currencies, CoinDesk had reported.

Crater "saw the growing crypto marketplace as an opportunity to create the illusion of My Big Coin as a legitimate service from which investors would yield a profit. His lies and deception inflicted real trauma, pain and hardship on the lives of 55 individual victims and their families who funneled their money into bank accounts," U.S. Attorney Rachael Rollins said in the statement.

See also: 6 Kinds of Crypto Scams and How to Avoid Them

CORRECTION (Feb. 1, 9:45 UTC): Corrects spelling of Crater in last paragraph.