A man alleged to have been an administrator of the 'Silk Road' - an online market for illegal goods - has been arrested in Co Wicklow.
The man was charged with offences under the Criminal Justice Mutual Assistance Act 2008 and was bailed to appear in court in Bray in January.
A number of laptops were seized as part of the arrest.
Silk Road sold black market goods online. It was in operation since January 2011, and allowed users to spend the virtual Bitcoin currency.
As well as drugs, the site sold fire-arms, counterfeit currency and had advertised for hitmen for hire.
In October, four men were arrested in the UK in relation to Silk Road. The same month in the US, Ross Ulbricht - who is alleged by the FBI to be the owner of Silk Road - was arrested in San Francisco on suspicion of drug trafficking, soliciting murder, facilitating computer hacking and money laundering.
Earlier this week a federal grand jury in the US state of Oregon charged four Portland residents with selling methamphetamine through Silk Road.
Prosecutors said the four conspired to sell 17 pounds of methamphetamine for a total of more than $600,000.