Arthur Budovsky, the founder and CEO of Liberty Reserve SA, was arrested by Spanish police at Madrid's Barajas International Airport in conjunction with a U.S. indictment of the firm for money laundering.
Budovsky was arrested along with his top deputy.
Liberty Reserve is estimated to have made more than 55 million transactions worldwide in the last seven years.
The U.S. Justice Department said criminals used Liberty Reserve to launder more than $6 billion in proceeds from illicit activities such as financial fraud, computer piracy, drug trafficking and child pornography.
The dismantling of the enterprise was undertaken jointly with U.S. authorities and has culminated with raids in several countries and five arrests: two in Madrid, two in the United States and one in Costa Rica, where Liberty Reserve is incorporated.
U.S. authorities began their investigation of the Web platform years ago suspecting that it was being used by cybercriminals.
The arrests - with an eye toward extradition - of Budovsky and his top deputy were made at the Madrid airport after the pair arrived on a flight from Morocco with the intention of continuing on to Costa Rica.
Liberty Reserve "facilitated global criminal conduct" and was created and structured "as a criminal business venture, one designed to help criminals conduct illegal transactions and launder the proceeds of their crimes," U.S. Attorney Preet Bharara said in an indictment unsealed Tuesday in New York. EFE