A man accused of founding a currency fund transfer business that allegedly helped criminals move money around the world has decided to fight U.S. efforts to extradite him from Spain.

Arthur Budovsky was due in court Monday after being detained last year at a Madrid airport while trying to return to Costa Rica, the alleged home of his Liberty Reserve currency transfer firm. His lawyer Gonzalo Boye says Budovsky will fight extradition. U.S. officials claim Liberty Reserve moved about $100 million through Costa Rican banks.

Budovsky, 40, renounced his American citizenship and lived in Costa Rica, where all online businesses are legal and there are no laws regulating them.

U.S. officials have said Liberty Reserve processed 55 million illicit translations, charging 1 percent on each one via middlemen.