The body of Pravin M Varughese was found on Tuesday in a wooded area in Carbondale, Illinois, police said.
Authorities do not suspect any foul play was involved in Varughese's death but the cause of his death is yet to be ascertained, Chicago Sun-Times reported.
Varughese, originally from Morton Grove, was last seen about 11 pm last Wednesday in Carbondale, police and his family had said previously.
His most recent post on Twitter, sent Wednesday night, read, "Bloody knuckles...Guess I was in a fight #backdown."
The family had offered a reward of $15,000 for information leading to the recovery of Varughese.
According to investigators, Varughese accepted a ride from a recent acquaintance on West College Street just before midnight that night, police said in a statement.
Varughese got out of the vehicle following a dispute and fled into a wooded area, the statement said.
While his exact cause of death is still being investigated, police believe the difficult terrain and low temperatures made it difficult for him to find his way out of the wooded area, it said.
"On behalf of our family, we wanted to thank you all for your kind words, endless support and prayers for Pravin," his family said in a statement posted on Facebook.
SIU Chancellor Rita Cheng, in a statement, called his death "a moment of unimaginable sorrow for the entire SIU community."
"This is a very difficult time. May we all find a spark of hope in the outpouring of support for Pravin and his family from people across Southern Illinois, the Chicago area and around the country and world during the past week and, certainly in the days ahead," Cheng said.
University officials are working with his family to find an appropriate way to honour Varughese, and counselling is available on campus for grieving students, Cheng said.