The operators of two exchanges for the virtual currency, Bitcoin, are under arrest in the United States, charged with money laundering.
The Department of Justice said the pair were engaged in a scheme to sell more than $US1 million in bitcoins to users of the Silk Road, an online drug marketplace. The site was shut down last year.
One of the men, Charlie Shrem, 24, was arrested on Sunday at JFK airport in New York. He operates an exchange, BitInstant.com and is a co-founder of the Bitcoin Foundation, a trade group that pushes the interests of Bitcoin as an alternative currency.
Robert Faiella, 52, was arrested on Monday at his home in Cape Coral, Florida.
The BBC reports Mr Shrem is accused of allowing Mr Faiella to use BitInstant to purchase large quantities of bitcoins to sell on to Silk Road users who wanted to anonymously buy drugs.