An 18-year-old Indian-American student, named Akul Dhawan, studying at the University of Illinois Urbana-Champaign in the US, died last month after going missing for several hours, media reports said.

The Champaign County Coroner's Office in Illinois this week said the Indian-American student died of hypothermia following "acute alcohol intoxication and prolonged exposure to freezing temperatures, which significantly contributed to his death."

The student was found dead on Jan 20 after his body was found on the back porch of a building near the university campus in west Urbana in the US state of Illinois.

There were signs of hypothermia when his body was recovered, however, the exact cause of death was under investigation by the campus police.

According to reports, Akul and his friends went out for drinks on Jan 20. Around 11:30 at night, they decided to go to the Canopy Club - a venue close to the campus that they had visited before that night.

However, he was denied entry by the staff of the club. He tried to enter the club "multiple times" but was repeatedly denied by staff," investigators said, adding that he also turned down two rideshare vehicles called for him, said reports.

Illinois and much of the midwest experienced brutal cold and freezing temperatures during that period, with wind chills dipping between -20 to -30 degrees.

Several calls were made to him that went unanswered and a friend contacted the campus police to search him.

According to police, an officer looked for Dhawan by driving his car "at a walking pace" near the "likely path" he would have taken back to campus but could not locate him.

The next morning, an employee of the university notified police and emergency medical services regarding "a man on the back porch of a building".

Police said that he was "dead at the time he was found".