Nothing of interest has been found by police, who have spent much of the day digging up the rear garden of a residential property in Tokoroa.
Police say they have completed their exploratory excavation work, and it "has not uncovered any items of interest at the house.''
The garden was targeted in a search for clues into the disappearance of a toddler more than 40 years ago.
The excavation work followed a privately funded sonar search of the area where 2-year-old Jefferie Hill went missing from outside his home on September 28, 1968.
At the time, an extensive search was carried out, including the the draining of the nearby Matarawa Creek.
A year later a coroner ruled that Jefferie had drowned in the creek, but his body was never recovered.
Detective Sergeant Kevan Verry of Tokoroa police said such cases were never closed and Jefferie was still listed as a missing person.
"We are always open to receiving new information that may shed new light on a case, and police will always investigate new information _ as we are doing in this instance.
"We felt that the report provided following the sonar search highlighted an area that warranted further investigation, hence the excavation work today.''
Mr Verry says the property excavated today was not owned by the current owners when Jefferie went missing.
Permission was granted by the current owners to undertake the exploratory work.
"Police will shortly leave the property,'' he said.
