Ngāti Hāua have placed a rāhui on the river from Victory Bridge to Whakahoro until further notice and while search and recovery efforts take place.
The rāhui means no swimming, fishing, gathering of kai, canoe paddling, jetboating, sightseeing or use of non-search related vessels can take place on and in the river between these locations.
Elsewhere, police are searching for a 56-year-old man in Ashburton, Christchurch, who was last heard from on August 26.
He is known to frequent the Ashburton, Christchurch and Nelson areas, police said, and is likely to be wearing a red-and-black check-pattern hoodie and black jeans.
Anyone with information on his whereabouts is asked to contact police on 105 with the reference number 250915/2603.