PITTSBURGH (CBS/AP) — A Revere man is one of 15 Chinese citizens who conspired to take college entrance exams on behalf of others or paid to have that done for them so they could obtain student visas, federal prosecutors in Pittsburgh said Thursday.

The newly unsealed indictment contends the alleged conspirators scammed tests run by Educational Testing Service and the College Board — such as the Scholastic Aptitude Test, or SAT.

READ MORE: Giant Pothole Damages 20 To 30 Cars On Route 1 South In Lynnfield

Six named in the indictment were clearly identified as students who paid up to $6,000 to have others charged take the tests.

Five defendants were test-takers, including the lead defendant, Han Tong, 24, of Pittsburgh, who even flew to California to take an SAT test for one person, the indictment said.

The precise role of the other four defendants — three of whose names remained under seal — was not clear, though the final named defendant allegedly helped with a fake passport.

The test-takers “impersonated others, and those others were able to use the fraudulent test scores to obtain F1 visas,” U.S. Attorney David Hickton told The Associated Press.

F1, or student, visas allow foreign citizens to remain in the country while they’re enrolled in American colleges or universities.

‘CHEATING THEIR WAY IN’

“These students were not only cheating their way into the university, they were also cheating their way through our nation’s immigration system,” John Kelleghan, the Special Agent In Charge of the Homeland Security Investigations office in Philadelphia said in a prepared statement.

Hickton wouldn’t say whether others students also benefited, or how many there may be, because the investigation was continuing.

For now, the indictment is confined to test-takers and students who benefited from tests administered in Pittsburgh and its suburbs since 2011. Investigators weren’t saying which, or how many, schools the students may have entered fraudulently.

READ MORE: Woman Charged With Stabbing Morton Hospital Worker Ordered To Undergo Evaluation

The test-takers allegedly used fake passports that contained the students’ personal information, but a picture of the test-taker substituted for the student, the indictment said.

Hickton said Princeton, New Jersey-based Educational Testing Service and the New York-based College Board were cooperating with the investigation. Hickton wouldn’t say whether the testing services alerted federal authorities to the alleged scheme, or vice versa, or whether it was discovered by the colleges and universities. A College Board spokesman planned a statement for later Thursday, but ETS didn’t immediately respond to a request for comment.

ETS administers the Test of English as a Foreign Language (TOEFL), the Graduate Record Examination (GRE), and the SAT, while the College Board oversees registration for the SAT.

The SAT is commonly used as an academic benchmark for college applicants. The TOEFL is given to foreign students wishing to study in the United States and the GRE tests a student’s readiness for graduate school.

BOSTON ARREST

Siyuan Zhao, 24, of Revere, Massachusetts, one of the students who allegedly benefited from the scheme, was arrested Thursday in Boston and prosecutors planned to ask a magistrate to jail him at least until he can be brought to Pittsburgh.

Tong and the 10 others whose names were publicized were being mailed summonses to appear in court soon.

The suspects face charges including conspiracy, counterfeiting passports, mail and wire fraud. The fraud counts each carry up to 20 years in prison; 10 years for counterfeiting passports; and five years for conspiracy.

Court records don’t list defense attorneys for any of the suspects, and the AP could not immediate locate phone numbers for them.

MORE NEWS: 3 Million Boppy Loungers Recalled After At Least 8 Infant Deaths

(TM and © Copyright 2015 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2015 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)