Ten of the suspects were arrested in Barcelona; the rest were arrested at various locations across the country.
Authorities said they were able to track the alleged porn peddlers through credit card payments made to websites registered in Belarus and Florida
The investigation began last year in collaboration with the U.S. Treasury Department and the state attorney's office in New Jersey.
“The operation highlights the importance of international police and judicial cooperation in the fight against this type of crime,” the ministry said in its statement Wednesday.
In November, Italy also rounded up suspects who allegedly paid for child pornography through a former Belarus-based billing processor called RegPay Co. The operators of RegPay were arrested in 2003. In January 2005, several of the company's principal executives were indicted for processing paid memberships to dozens of child porn websites.
Formerly known as Trustbill, RegPay ran child porn website PedoWorld.com, while also serving as the site's credit card processing company.