Police have named the man who has been missing in Canterbury's Waimakariri River.
A police spokeswoman said he is 38-year-old Kapuaiwaho "Kapu" Waretini of Auckland.
"Kapu's whānau have asked for privacy at this time.
"Search and Rescue volunteers are continuing to search the beach areas near the Waimakariri river mouth today."
Police were called when the man's friends could not find him after he went swimming near the Waimakariri Bridge on Saturday.
The dive squad began its search on Monday morning and a helicopter joined on Tuesday with no luck.
Their search efforts focused on the area between the State Highway 1 bridge and the Old Waimakariri bridge.
Local runanga have placed a rahui on part of the river.
Despite police searching the river with help from the Kaiapoi Coastguard on Saturday night, the man could not be found.
Police said anyone with information about the incident should phone 105 and quote file number 210130/5446.
The 19-year-old disappeared without her wallet or mobile phone.