Amherst College, along with several other colleges including Williams, Middlebury and Tufts, is being investigated by the DOJ for alleged violations of federal antitrust laws in its early-decision program.

The colleges were notified on April 5 and 6 by letters from the DOJ requesting the schools to maintain records of all communications between officials at other schools regarding applicants and any communication that indicates decisions that were made about applicants.

The letter sent to schools said that it would be investigating “a potential agreement between colleges relating to their early decision practices,” according to the New York Times.

The department, which aims to enforce laws surrounding competitive business practices, has not yet specified exactly why the colleges are being investigated for antitrust violations. In the past, other colleges have faced similar scrutiny. The Antitrust Division investigated Ivy League universities in the 1990s for sharing information and collaborating on financial aid offers.

It is still unclear how many schools were contacted in the investigation, but Dean of Admissions Katie Fretwell confirmed that Amherst has been contacted by the department and that the school is “fully cooperating with their request for information.” She refused to comment any further.

According to an article in the Boston Globe, it is commonly-accepted practice for schools to share early-decision information with other colleges to make sure that students are not applying early-decision to more than one school, which breaks the rules of early-decision.

In an article published in the U.S. News and World Report in 2016, Fretwell explained that Amherst and around 30 other schools typically share lists that identify the students who were admitted through the early decision program.