A federal judge in New York sentenced the co-founder of the purported cryptocurrency OneCoin to 20 years in prison on Tuesday for what prosecutors called a $4 billion fraud, according to Reuters. 

U.S. District Judge Edgardo Ramos in Manhattan sentenced Karl Sebastian Greenwood, a dual citizen of Sweden and the United Kingdom, who pleaded guilty to fraud and money laundering charges in December 2022.

Ramos also ordered Greenwood to forfeit $300 million.

Greenwood has been detained in New York since his 2018 arrest in Thailand and extradition to the United States over his role in promoting OneCoin.

Prosecutors had sought a sentence of at least 30 years for Greenwood, who they said was OneCoin’s “primary promoter” who touted it as the next Bitcoin. In reality, OneCoin was a pyramid scheme that defrauded at least 3.5 million people, they said.

Greenwood’s attorneys had asked for a sentence of time served, citing harsh conditions during his detention.

Greenwood founded OneCoin in Sofia, Bulgaria in 2014 alongside Ruja Ignatova, a German citizen who prosecutors say is also known as the ‘Cryptoqueen.’ The FBI named her to its top ten most-wanted list last year.

Ignatova remains at large, prosecutors said.

An attorney for Greenwood declined to comment.

The sentence comes as prosecutors in Manhattan gear up for the trial of FTX founder Sam Bankman-Fried, who has pleaded not guilty to fraud and conspiracy charges stemming from the November 2022 collapse of his now-bankrupt cryptocurrency exchange.