Eamonn Daniel Higgins spent seven years attending college.

Between 2002 and 2009, he attended 10 different schools in Southern California, including Cal State Los Angeles, Irvine Valley College and Santa Monica College, according to federal prosecutors. During that time, he studied sociology, marketing, English, business and math.

The problem was that Higgins hadn’t registered for any of the courses, authorities said. Rather, dozens of foreign students -- mostly from the Middle East -- were paying him to sit in class, take exams and write papers for them so their student visas would remain valid, according to a charging document filed in the case. Students paid up to $1,500 for course assignments and finals and up to $1,000 for English and writing proficiency exams, the document said.

Investigators with U.S. Immigration and Customs Enforcement said the demand was so great that he hired employees, including a blond woman who they believe posed as an Middle Eastern man to take a test. Agents are continuing to investigate the case and believe Higgins had several co-conspirators.

On Monday, Higgins, 46, pleaded not guilty in federal court in Santa Ana to conspiracy to commit visa fraud. During the brief hearing, Higgins told the judge he wasn’t working. He faces up to five years in federal prison if convicted.