Two people have died and one person remains missing after a boat capsized on the Riverton bar this afternoon (3 Aug).

Emergency services were alerted to the capsize at 2.55pm today.

The boat, a recreational craft, capsized approximately 100 metres off shore with five people on board.

Two people were recovered alive from the water and brought to shore before being transported to Southland Hospital.

A third person was unresponsive when brought to shore and tragically was unable to be revived by emergency services staff.

A fourth person was located deceased in the water, and the search for the fifth person remains ongoing.

A significant resource has been deployed in response to this incident, including Police, Coastguard Riverton, Coastguard Bluff, Hato Hone St John, Fire and Emergency New Zealand, and SAR volunteers.

Southland Area Commander Inspector Mike Bowman said this is an absolute tragedy and our hearts go out to all those impacted by this devastating incident.

Family and next of kin notifications are currently being undertaken, he said.

No further information regarding the deceased and missing is currently available.