Three men, including one based in Ireland, have been indicted in the US in connection with Silk Road, the internet black-market bazaar in which illegal drugs such as heroin and cocaine can be purchased for the digital currency bitcoin.

The indictment, unsealed in New York, charges the three with conspiracy to engage in narcotics trafficking, computer hacking and money laundering.

One of the men was presented before a court in Richmond, Virginia, on Friday after being arrested the day before, according to the Manhattan US Attorney’s Office.

A second was arrested in Ireland and the third was arrested in Australia, the office said. Lawyers for the defendants could not immediately be located for comment.

A Garda spokeswoman confirmed that gardaí arrested a 25-year-old man after a search at a house in Johnstown Court, Kilpedder Co Wicklow in connection with an international investigation into online offences.

A number of computers and USB sticks were seized in the search, the spokeswoman said. The man was detained at Bray Garda station charged under section 74 of the Obstruction of the Criminal Justice Act.

He was released to appear at Bray District Court on January 13th at 10.30am.

The charges followed the arrest in October of alleged Silk Road founder Ross Ulbricht, who is known online as ‘Dread Pirate Roberts’.

US authorities shut Silk Road down at the time of Mr Ulbricht’s arrest, although last month a new marketplace carrying the same name and appearance debuted online.

Two of the three men arrested allegedly acted as site administrators for Silk Road, while the third was allegedly the primary moderator for the website’s discussion forums, the indictment said.

According to the indictment, the three men were part of Mr Ulbricht’s “small support staff” for Silk Road.

Salaries for the employees ranged from $50,000 to $75,000 a year, the indictment said.

The indictment accuses them of conspiring to violate US narcotics and computer hacking laws.

Silk Road, in addition to providing a venue for illegal drug sales, had also enabled the sale of “malicious software” intended for hacking, the indictment said.

Mr Ulbricht (29), was charged in a separate criminal complaint in October.

He is being held at a metropolitan detention centre in Brooklyn after last month losing a petition to be released on bail.

Mr Ulbricht’s lawyer, Joshua Dratel, has been discussing a possible plea deal with prosecutors, according to court filings.

Mr Ulbricht is also under federal indictment in Baltimore, Maryland, in a case relating to a murder-for-hire plot.

On December 6th, assistant US attorney Serrin Turner asked US magistrate judge James Francis for a 30-day extension of the deadline to file an indictment, saying that he and Mr Dratel had spoken in October and November about a possible resolution of the case and planned to continue talking.

The judge granted the request, which was not opposed by Mr Ulbricht. Mr Dratel did not respond to a request for comment on Friday.

Additional reporting: Agencies