A 27-year-old man who died on a north Queensland street in suspicious circumstances was a New Zealand citizen.

The unnamed man was found unconscious by a passerby on a footpath in downtown Cairns.

Police say he had lived with his brother in Cairns for several years.

Detective Senior Sergeant Ed Kinbacher says the man became separated from his girlfriend near the Railway Hotel and was found injured just over an hour later.

He was pronounced dead by paramedics a short time later.

The inquiry into how he suffered those injuries continues.