An agent of the U.S. Drug Enforcement Administration (DEA) has noted that Bitcoin's (BTC) role in crimes has dropped to just 10 percent of transactions, while transactions themselves have "grown tremendously," Bloomberg reports August 7.

In an interview, DEA special agent Lilita Infante - who is a member of the 10-person Cyber Investigative Task Force - said that the ratio of legitimate to illegitimate Bitcoin transactions had flipped over the past five years, noting

"The volume has grown tremendously, the amount of transactions and the dollar value has grown tremendously over the years in criminal activity, but the ratio has decreased."

The concept of criminals turning to cryptocurrency as an alternative to cash has traditionally formed a central argument used by those critical of Bitcoin's future.