As police investigate the death of a 20-year-old Texas State University student over the weekend, the university has suspended activities of all Greek fraternity and sorority chapters.

Police are investigating after a 20-year-old Texas State University student died over the weekend.

Police said Matthew Ellis, 20, died off-campus. Ellis of Humble, Texas, was a sophomore in the College of Business Administration.

According to the The University Star, the university's student paper, Ellis died in his sleep Nov. 12 following his fraternity's initiation. He was a member of Phi Kappa Psi.

The City of San Marcos announced Tuesday that police responded to the Millennium Apartments after receiving a call Monday around 11:35 a.m. in reference to a subject not breathing. Ellis was found unresponsive and declared deceased at 12:28 p.m. After initial interviews with individuals on scene, it was determined that Ellis was found by friends a little after 11 a.m. on Monday.

City officials said that an autopsy was ordered by Judge Maggie H. Moreno and his body was sent to the Travis County Medical Examiner's Office. Preliminary investigation indicates that alcohol may have been a factor in his death but investigators are awaiting toxicology results.

The San Marcos Police Department is currently investigating. Ellis' next of kin have been notified, officials said.

Denise M. Trauth, Texas State's president, said in a statement that all Greek activities are suspended. Here's her full statement:

As president of Texas State University, I am deeply saddened by the tragic death of one of our students who attended an off-campus social event on Sunday evening hosted by members of a university fraternity. Following a call from friends, officers with the San Marcos Police Department found Matthew Ellis, a Phi Kappa Psi pledge, unresponsive on Monday morning at an apartment off campus. He was pronounced dead after EMS personnel were unable to revive him. My thoughts are with his family, friends, and the Texas State Community.

As a result of this tragedy, I have suspended activities of all Greek fraternity and sorority chapters at Texas State. These chapters are prohibited from holding new-member events, chapter meetings, social functions, and philanthropic activities until a thorough review of the Greek Affairs system is completed.

I have asked Dr. Joanne Smith, Vice President for Student Affairs, who has responsibility for the Greek Affairs system, to immediately initiate this review and propose recommendations for reinstating fraternity and sorority chapters that demonstrate a commitment to the core values of Texas State and the ideals established by their respective national organizations.

It is imperative that our entire university community develop a culture that places the highest priority on the safety of its students, faculty, and staff.

Phi Kappa Psi released the following statement:

"We are heartbroken by the death of Texas State University student and Phi Kappa Psi new member Matthew Ellis," said Phi Kappa Psi Executive Director Mark Guidi. "Our thoughts and prayers are with his family, friends and the entire TSU student body during this difficult time."

The chapter had been suspended by Phi Kappa Psi Fraternity, Inc. last week for unrelated matters, and will remain suspended while the investigation continues. Phi Kappa Psi will continue to work closely with the TXSU administration and law enforcement during their review of this matter, and have advised all members to cooperate fully."