Police say the death of a man found with serious injuries in Grimsby is "unexplained."
The 46-year-old man was discovered at a property on Oxford Street on Wednesday night.
Emergency services attended at around 11.40pm, but the man was later pronounced dead at the scene.
Police are still trying to trace the victim's next of kin.
A spokesman for Humberside Police said: "Investigations into the circumstances are underway however at this time his death is being treated as unexplained.
"Exhaustive enquiries have been made since last night to trace the man’s next of kin but to no avail. These enquiries are continuing this evening."
A 47-year-old man has been arrested in connection with the incident and is currently in police custody being questioned.
Anyone with any information is urged to call 101. Alternatively call Crimestoppers on 0800 555 111.