DURHAM, N.H. — A University of New Hampshire student who was found dead in a marshy area had drowned and the manner of his death was accidental, according to an autopsy released Wednesday.

Police in Durham released the information in the death of Vincenzo “Vinny” Lirosi, 22, of Whitman, Massachusetts. He was found Sunday.

Durham police said Lirosi was out drinking with friends early Saturday before he went to a Sigma Chi fraternity party and got into a fight.

Sigma Chi has been temporarily suspended as police investigate Lirosi’s death. The chapter said it is complying with the interim suspensions issued by the Sigma Chi International Fraternity and the university and it is cooperating with authorities.

The chapter said in a statement Tuesday that Lirosi had gained access without permission to its “welcome home” event for a member who was returning from military service.

Lirosi “became unruly, and disturbed other attendees,” the statement said. “Mr. Lirosi left the event shortly after his arrival and was last seen walking away from the event under his own power.”