DURHAM, New Hampshire — The University of New Hampshire fraternity that has been temporarily suspended as police investigate a student’s death said that student had gained access without permission to its “welcome home” event for a member who was returning from military service.

“We are saddened to learn of the death of Vincenzo Lirosi, an uninvited guest who died after leaving an event held by some members of our chapter,” Sigma Chi said in a statement late Tuesday. “We extend our sincere condolences to his friends and family. We are fully cooperating with authorities as they investigate the circumstances of his death.”

Lirosi, 22, of Whitman, Massachusetts, was found dead Sunday in a marshy area in Durham. Autopsy results have not been released, but officials said they don’t believe the death was suspicious.

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

Sigma Chi said Lirosi “gained access to the event without permission, became unruly, and disturbed other attendees. Mr. Lirosi left the event shortly after his arrival and was last seen walking away from the event under his own power.”

The chapter said it is complying with the interim suspensions issued by the Sigma Chi International Fraternity and the university.