Cleveland Police said in a statement that they were called to a house in The Green, in Seaton Carew, at just after 2pm on Tuesday after they were contacted about his “sudden death”.
A post mortem is due to take place while inquiries continue and the force have offered his family their sympathies.
A spokesperson for the police said in the statement on Wednesday afternoon: “Police received a call regarding the sudden death of a man believed to be aged in his 60s at a property on The Green, Seaton Carew, around 2.10pm on Tuesday, July 27.
“Officers are currently treating the death as unexplained and a post mortem is due to take place in due course.
"The man’s family have been informed and our thoughts remain with them at this extremely difficult time.”
Further details are expected to be released about the death and investigation later in the week.