Former U.S. trading commissioner Bart Chilton has said that bitcoin is “not a scam or fraud,” according to a news report.

Talking to Fox Business, Chilton made his comments in response to former Federal Reserve chairman Alan Greenspan who raised concerns on the sustainability of bitcoin last week – reportedly stating that cryptocurrencies do not have any “backing.”

Chilton said:

“I don’t think it’s, you know, a fraud, like [JPMorgan CEO] Jamie Dimon said, or a pyramid scheme like [Russian] President Putin said, I mean, people are actually using bitcoins to purchase things. So, that’s not a scam or a fraud.”

“I do think it’s sustainable, I don’t know if it’s sustainable at these prices,” he told the news channel.

Elsewhere in the interview, Chilton, who was commissioner at the U.S. Commodity Futures Trading Commission from 2007–2014, expressed the hope that bitcoin regulations will bring some protections for consumers but will not be “overly zealous.” He added that CME Group’s plans to launch bitcoin futures by the year’s end will bring needed regulations to the space.

His statements come soon after European Central Bank president Mario Draghi said that cryptocurrencies are too “immature” to be considered for regulation.

Bart Chilton image via Mathew Greenfield/YouTube