The Department of Education has opened a "preliminary investigation" into the $25 million college admissions cheating scandal in which 50 people were criminally charged, according to a letter sent to one of the universities involved.

The investigation overseen by the department's enforcement unit will examine where there were any violations to laws and regulations related to federal financial aid programs, a letter sent to the University of Southern California president stated.

In order to continue participating in any Title IV or Higher Education Act programs, a school must demonstrate that it is "adequately administrating" those programs in accordance to the law, the letter said.

That includes referring any employee, agent of the institution, or recipient of federal funds to the department's inspector general who "may have engaged in fraud, misrepresentation" or other illegal activity, the department said.

The Education Department requested documents from USC that included the school's admissions policies and the names of students whose admission was mentioned in the FBI's investigation in the admissions scandal.

"We will fully cooperate with the DOE as we are with the Department of Justice's ongoing investigation, and will continue to comply with all laws and regulations," USC said in a statement Tuesday,

Wake Forest University, Stanford University, Georgetown University, the University of San Diego, and the University of California Los Angeles are also a part of the department's investigation, the schools confirmed in statements Tuesday.

"We are committed to an admissions process that includes a fair, holistic review of each application," Georgetown said in its statement.

Yale did not confirm it received a letter but said Tuesday the university was made aware of the investigation.

The alleged scam focused on getting students admitted to elite universities as recruited athletes, regardless of their athletic abilities, and helping potential students cheat on their college exams, according to the federal indictment.

At least one student involved in the scandal has had their acceptance rescinded to Yale as a result of the scandal, the Yale Daily News reported Monday.

Yale has also launched its own internal review to discover "whether others have been involved in activities that have corrupted the athletic recruitment and admissions process."

Mark Riddell, a 2004 Harvard graduate, allegedly secretly took college board exams for students between 2012 and this past February. He is expected to plead guilty to charges of conspiracy to commit mail fraud and money laundering, according to court documents.

Two of the most high-profile names ensnared in the scandal, actresses Lori Loughlin and Felicity Huffman, are scheduled to appear in court in Boston next month.

Loughlin, best known for her role on "Full House," and her fashion designer husband, Mossimo Giannulli, allegedly agreed to pay bribes totaling $500,000 to bolster the chances for their two daughters, Olivia Jade and Isabella Giannulli, to get admitted to the University of Southern California. Both girls are still enrolled at the school, according to a USC spokesperson.