A man's body was found in a submerged car recovered from the Mataura River today, say Southland Police.

A vehicle left Holz Road and entered the river at 5.30am, say Southland Police.

Marine SAR and the Coastguard were unable to confirm if anyone was still in the vehicle. The Police National Dive Squad were called to assist.

Earlier this afternoon Police Dive Team members confirmed a single occupant was found dead in the vehicle.

Police have also begun a serious crash investigation to determine how the vehicle came to be in the river and are unable to comment further while this investigation is ongoing.