Police are investigating the unexplained death of a man in Christchurch.

Emergency services were called to a property in Milton St, in the suburb of Sydenham, at 12.30pm on Sunday.

He could not be revived.

Detective Senior Sergeant Dan Overend said police were making inquiries on behalf of the coroner to establish the circumstances.

There would be a police presence at the property while a scene examination was carried out.

A post-mortem examination was scheduled to take place in due course.

Police did not believe there was any risk to the wider public, Overend said, and support was being given to people affected.