SAN MARCOS, Texas – Authorities believe alcohol may have played a factor in the death of a 20-year-old Texas State University student.

Friends found Matthew McKinley Ellis unresponsive about 11:35 a.m. Monday at the Millennium Apartments, according to the San Marcos Police Department.

Ellis is from Humble.

READ: Definition of hazing in Texas

Authorities said Ellis was a pledge for Phi Kappa Psi fraternity. He was pronounced dead at 12:28 p.m.

An autopsy has been ordered. Investigators believe alcohol may have been a factor in his death, but are awaiting toxicology results from the autopsy, which is expected to take 6-8 weeks.

Ellis was an active student at Texas State University and lived on campus. He was staying at the off-campus apartment complex with four other fraternity members. It is not clear if they are members of the fraternity where Ellis was pledging.

The investigation

University spokesperson Matt Flores said the university is investigating whether the fraternity held any social events preceding Ellis' death.

Flores confirmed that the Phi Kappa Psi fraternity has been under investigation by the university since Oct. 4. The investigation stems from allegations of misbehavior within the fraternity.

The initial complaint was brought to Greek Affairs' attention on Sept. 21 and a formal review was launched Oct. 4. It is an ongoing review.

WATCH: San Marcos Police Department provides updates on student's death

During a press conference Tuesday, authorities said it is too early to tell if Ellis' death is a result of hazing. They also said they have had no previous knowledge of alcohol-related incidents with the fraternity.

Authorities also said they believe the drinking was done at a private fraternity event, not in public.

If it is determined that Ellis' death is hazing-related, charges could range from providing alcohol to a minor to manslaughter.

No arrests have been made at this time.

Greek life suspended

As a result of Ellis' death, Texas State University has suspended activities of all Greek fraternity and sorority chapters at the school.

The 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."

This is not the first time this year an incident like this has happened.

February:

Penn State University: Sophomore Tim Piazza died after an alleged hazing ritual while he was pledging Beta Theta Pi.

September:

Louisiana State University: Maxwell Gruver, an 18-year-old Phi Delta Theta pledge, died in what police are investigating as a possible hazing incident.

November:

Florida State University: Andrew Coffey’s death is believed to be alcohol-related. He was pledging Pi Kappa Phi. The death resulted in the suspension of all Greek activities on campus.

Phi Kappa Psi released the following statement on the incident:

"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 from all operations 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 TSU administration and law enforcement during their review of this matter, and have advised all members to cooperate fully."

Texas State University President Denise M. Trauth issued the following statement:

"As president of Texas State University, I am deeply saddened by the tragic death of one of our student 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."