A student was found dead with unexplained injuries outside a house in Leeds, police said.
Leeds Beckett student Harry Loker, 21, was found collapsed on Royal Park Avenue in Hyde Park.
His family said he was a "devoted son, brother and perfect grandson" and his death had left them "broken".
West Yorkshire Police said Mr Loker was socialising with friends in Leeds on Thursday evening and left for home in the early hours of Friday.
Officers were called at 09:15 BST on Friday to reports a man had been found collapsed.
Det Ch Insp Jaz Khan said: "A post-mortem examination revealed Harry had a number of injuries which cannot presently be accounted for. His death is being treated as unexplained."
He said officers were keeping an "open mind".
'Pain in our hearts'
"We are treating Harry's death as unexplained, as we continue to build a picture of his movements after he left the city centre," Mr Khan said.
"I am appealing to anyone who may have seen Harry on Thursday night, or the early hours of Friday morning to come forward as they may hold vital information in helping us understand what has happened.
"Harry's family are understandably devastated with the news, and officers are continuing to support them at this time."
The family said: "Harry was a devoted son, brother and perfect grandson and we could not have asked for more.
"We as a family were extremely proud of Harry and all his achievements and he will be sorely missed.
"This terrible terrible incident has broken us as a family and leaves pain in our hearts."