BOSTON (Reuters) - The U.S. Justice Department on Thursday backed a lawsuit accusing Harvard University of discriminating against Asian-American applicants, throwing its support behind a case that could impact the use of race-based college admissions.

The department, which has been investigating Harvard for potential civil rights violations over its affirmative action policy, made its argument in documents filed in federal court in Boston, where the case is scheduled to go to trial in October.

The Justice Department argued that Harvard had failed to prove that its use of race as a factor in deciding which students to admit had not resulted in it illegally discriminating against Asian-Americans.

Instead, the department said the evidence in the lawsuit by Students for Fair Admissions showed Harvard’s admissions process “significantly disadvantages” Asian-Americans compared with other groups.

“No American should be denied admission to school because of their race,” U.S. Attorney General Jeff Sessions said in a statement.

Cambridge, Massachusetts-based Harvard said in a statement that it was “deeply disappointed” by the department’s action and will defend the right of colleges to consider race as an admissions factor.

Supporters of Harvard, including the American Civil Liberties Union, assailed the Trump administration’s decision to intervene in the case, with some calling the department’s position an assault on efforts to promote campus diversity.

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The U.S. Supreme Court has ruled that universities may use affirmative action to help minority applicants get into college. Conservatives have said such programs can hurt white people and Asian-Americans.

In 2016, the top court rejected a challenge to a University of Texas program designed to boost the enrollment of minority students. The challenge was brought by a white woman.

SFFA is headed by prominent anti-affirmative action activist Edward Blum, who found the woman in the 2016 case. Harvard has called SFFA a “litigation vehicle designed to advance the ideological objectives of its founder.”

After President Donald Trump, a Republican, took office last year, the Justice Department began investigating whether Harvard’s policies are discriminatory because they limit Asian-Americans’ acceptance.

In court papers, SFFA claimed an Asian-American male applicant with a 25 percent chance of admission would have a 35 percent chance if he were white, 75 percent chance if he were Hispanic and 95 percent chance if he were black.

A Harvard research division found in 2013 that over a decade Asian-American admission rates were lower than those for whites annually even though whites outperformed Asian-American applicants only on a subjective personality rating, the SFFA said.