A homicide investigation is underway in Invercargill after a man died early this morning.

Police received a report just before 12.45am that two men were injured on Don Street in the vicinity of the Invercargill District Court building.

Detective Inspector Stuart Harvey said when police arrived, one man was found unconscious with stab wounds. 

He died at the scene.

The second man was taken to hospital in a critical condition with similar injuries and he has now undergone surgery. 

He remains in a critical condition.

A scene guard was in place overnight on Don Street and a forensic examination of the area will continue today. 

To allow this to happen, cordons are in place on Don Street between Kelvin Street and Dee Street.

Police want to speak to anyone who was either walking or driving through the vicinity of Don Street at the time. 

Anyone with information should contact Police on 105 and quote event number P050337575.

Information can also be provided anonymously via Crime Stoppers on 0800 555 111.

This incident is not linked to the fatal crash yesterday afternoon on Queens Drive.