Barclays is assisting in the money laundering probe being conducted by US authorities after one of the seized Liberty Reserve accounts were found to be run by the UK-based bank.
The authorities have accused Liberty Reserve of laundering more than $6 billion in criminal money.
Papers filed by the US Department of Justice reveal Liberty Reserve has 17 bank accounts in the troubled nation of Cyprus and it is understood Barclays is not being accused of any wrongdoing.
The court documents said the Barclays account was in the name of Liberty Reserve founder Arthur Budovsky.
A spokesman for the bank said: "Barclays can confirm it is co-operating with the investigation, following the notification it received from the authorities."
The Department of Justice has alleged seven people are involved in running the money laundering operation set up Liberty Reserve as a "criminal business venture", which has been specifically designed to help criminals.
By Tony Aynsley