The body was found today in the Waimakariri River, near Kairaki.
Police were called to the area about 6.30am.
While formal identification had yet to take place, police said they believed the body to be that of Kapuaiwaho "Kapu" Waretini (38), of Auckland.
Mr Waretini failed to return from swimming in the river last Saturday.
His death will be referred to the Coroner.