The U.S. Department of Justice has charged four Chinese nationals in connection with a college admissions scam. Two of the students were admitted to schools in Massachusetts.

The Justice Department says a student at Hult International Business School in Cambridge took the TOEFL, an English-proficiency test, for three other students.

Colleges and universities require minimum TOEFL scores for most foreign applicants, and prosecutors say the three students submitted the fake scores to gain admission to Northeastern University, Penn State University and Arizona State University, then used their admissions to illegally obtain student visas.

Experts in higher education point out that exam schemes like this are rampant and undermine both academic integrity and the country's student visa program. Last year, an investigation by the news agency Reuters found that a private education company in China is helping students game admissions tests.

Two years ago 15 Chinese nationals were arrested and charged in a similar scam. 

In a statement, Northeastern, which receives more than 50,000 undergraduate applications each year, said the university relies on testing agencies to verify the identity of those taking standardized tests.

If convicted, the defendants face five years in prison and deportation.

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