Bozhidar Bakalov, a US citizen originally from Bulgaria has been sentenced to a three-year prison term by a Cincinnati court for ‘massive marriage fraud'.

Federal authorities in Cincinnati say many couples were part of a massive marriage fraud scheme that involved hundreds of immigrants who sought and were sometimes granted legal residence in the US through phony marriages to citizens.

US Prosecutors stated that Bakalov was the creator of the scheme. They added that Bakalov, a former Procter & Gamble manager, kept spreadsheets, set up a client referral service and ran his illegal match-making service like any other business.

Authorities aren't sure how much money Bakalov made before he went to jail, but they say he charged thousands of dollars to connect Russian and Eastern European men to American women willing to fake a marriage for cash.

Documents made public recently in federal court describe an elaborate, long-running operation that authorities believe is the largest of its kind in the region's history.

"The base of operations was centered in Cincinnati, but it's nationwide," said Rich Wilkens, the agent in charge of Immigration and Customs Enforcement in Cincinnati. "It's national in scope."

Bakalov's lawyer, Brian Goldberg, said his client thought he was providing a legitimate service in which the men got to stay in America, the women got paid and he made a profit.

Such practices were common in Bulgaria, Goldberg said, and Bakalov didn't know until his arrest that he was breaking the law.

Wilkens said the Cincinnati case, dubbed "Operation Honeymoon's Over," still is under investigation and more people could be charged.