Federal prosecutors on Thursday announced the indictments of 15 Chinese nationals who they say cheated on college-entrance exam as part of an attempt to fraudulently obtain U.S. student visas, the Associated Press reported.

Some of the suspects took the exams, such as the Scholastic Aptitude Test, or SAT, on behalf of other students, while others paid for such services, according to investigators. The scheme involved test-takers and students who benefited from the exams run by Educational Testing Service and the College Board, the newswire detailed.

Students paid up to $6,000 to have others take the tests; one defendant, 24-year-old Han Tong, flew to California from Pittsburgh to take an SAT test for another individual, according to the 35-count indictment, returned on May 21 in the Western District of Pennsylvania.

The suspects face charges including conspiracy and counterfeiting passports, as well as mail and wire fraud, the AP detailed. The fraud counts each carry a prison sentence of up to 20 years; counterfeiting passports can be punished with up to 10 years, and conspiracy with up to five years behind bars.

The test-takers "impersonated others, and those others were able to use the fraudulent test scores to obtain F1 visas," David Hickton, the United States attorney for the District of Western Pennsylvania , told the newswire in reference to a category of visa issued to international students who attend an academic program at a U.S. college or university.

Hickton told the New York Times that some of the defendants were admitted to universities around the country, a prerequisite of applying for a student visa at a U.S. diplomatic mission abroad.

"If they are, in fact, not supposed to be students of the American college because their admission was fraudulently obtained, then their visa has been fraudulently obtained, as well," Hickton contended.

Ten of the accused reside in the United States and two in China, which is home to about 31 percent of the international students in the country, according to the newspaper. Hickton said that he hoped that Chinese officials would cooperate with the U.S. investigation.