Man dies after found unconscious on street

A man has died after he was found lying unconscious on a street in Sydney's southwest.

Emergency services found the man about 5am on Monday after a resident spotted him on a pathway behind houses on Huntley Street in Cartwright.

Despite the best efforts of paramedics, the man, aged in his 50s or 60s, could not be saved.

Officers have been told he was seen walking in the area "in an impaired state" late on Sunday night, a police spokeswoman told AAP on Monday.

A crime scene has been established and police will await the results of a post-mortem to determine how he died.

Police said it's too early to determine if the incident was suspicious.