Grave fears are held for a man believed to have fallen into the Clutha River in central Otago today.
The 27-year-old from Roxburgh in central Otago was working in the area and headed to the river to collect water samples at around 12.30pm, but didn't return.
Police were called shortly before 3pm this afternoon.
Helicopters, police staff, coastguard and search and rescue staff are carrying out air, river and ground searches focused on an area near the Talla Burn Power Station on the Milennium Track Road near Beaumont.
Police say "items of interest" have been found in the river and grave fears are held for the man's safety.
His family are at the scene with police and victim support staff, with some family members joining the search party.
He won't be named until other family members have been informed he is missing.
- NZ Herald staff