The FBI arrested Silk Road owner Ross William Ulbricht, 29, known as "Dread Pirate Roberts," in San Francisco on Tuesday, according to court filings.

Federal prosecutors in New York charged Ulbricht with one count each of narcotics trafficking conspiracy, computer hacking conspiracy and money laundering conspiracy, according to the filing.

"Silk Road has emerged as the most sophisticated and extensive criminal marketplace on the Internet today," FBI agent Christopher Tarbell said in the criminal complaint. According to Tarbell, the site was used by "several thousand drug dealers" to sell "hundreds of kilograms of illegal drugs."

The site, which had operated since early 2011, also offered tutorials on hacking ATM machines, contact lists for black market connections and counterfeiters, and guns and hit men for sale, according to the charges.

Authorities also seized $3.6 million worth of digital currency Bitcoin, which was used instead of cash or credit cards to complete transactions on Silk Road. The charges against Ulbricht said his website generated sales of more than 9.5 million Bitcoins, roughly equivalent to $1.2 billion.

The raid on Wednesday was not the first time the U.S. government has made arrests related to Silk Road. Earlier this year, authorities in South Carolina arrested Eric Daniel Hughes, who used Silk Road under the name Casey Jones, and charged him in state court with drug possession. The Drug Enforcement Agency seized units of the digital currency Bitcoin, which Hughes allegedly used to purchase drugs from the online market.

Bitcoins, which have been around since 2008, first came under scrutiny by law enforcement officials in mid-2011 after media reports surfaced linking the digital currency to Silk Road.

(Editing by Gerald E. McCormick and Jeffrey Benkoe)

By Emily Flitter