A former undercover drug agent pleaded guilty Wednesday to extortion and other charges after authorities said he used his position to steal more than $700,000 in digital currency, most of it siphoned from an online drug bazaar known as Silk Road that he infiltrated as part of a federal investigation.

Carl M. Force, dressed in the orange garb of the San Francisco jail and shackled at the ankles, pleaded guilty to extortion, money laundering and obstruction of justice in federal court.

The former Drug Enforcement Administration agent could face a maximum sentence of 20 years in prison when sentenced in October.

"He had a stellar, 15-year career with the DEA except for this one blip," Force's attorney Ivan Bates said outside of court.

Inside court, Bates told U.S. District Judge Richard Seeborg that Force suffers from anxiety and depression.

While with the DEA, Force, 46, was tasked with masquerading as a big-time drug dealer who had connections to hit men, infiltrating Silk Road and communicating with the online drug bazaar's founder Ross Ulbricht.

Ulbricht was recently sentenced to life in prison for his role in managing the Silk Road website, which rang up more than $200 million in sales.

Serving in his undercover role as "Nob," Force told Ulbricht he had inside information about the federal investigation of Silk Road and began selling him tidbits about the probe, authorities said.

Force also created another persona, "French Maid," who purported to have inside information on the probe that he sold to Ulbricht.

Force also invested in a company that brokered the digital currency bitcoin and served as the firm's chief compliance officer while still with the DEA.

During his time with the company, Force used his position to seize $300,000 from a customer and transfer it to his private account, authorities said.

Authorities say former Secret Service agent Shaun Bridges previously agreed to plead guilty to theft charges involving the separate siphoning of funds from Silk Road. Bridges is scheduled to enter his plea in August.