It was initially thought Young was last seen alive at the Dinsdale shopping centre on March 9, however after further inquiries police had discovered he had been seen on March 12, the night police believe he was killed, Loughrin said.
A number of people connected to Young had been spoken to in order to build a picture of his last movements.
"Mr Young was last seen alive on the evening of Thursday, March 12 in the Enderley/Fairfield area of Hamilton.
"We believe this was likely the night he was killed.
Police investigating the death of Sao Young at a Casey Ave property this morning. Photo / Nikki Preston
Hamilton police are today searching a property on Casey Ave in relation to the death of 40-year-old Sao Young. Photo / Police
"His body was discovered at a rural property in Horsham Downs on Monday, 13 April - it was likely transported there after his death."
An investigation team of 30 people, including specialist staff, were now working to help provide closure for Young's family.
Young arrived in New Zealand from Cambodia in 1992 and has been described by many as a gentle person who would not harm anyone.
Young had lived at a variety of Hamilton houses, most recently in the suburbs of Chartwell and Maeroa. He would often walk or catch the bus as he didn't own a vehicle.
Police would like to hear from anyone who may have seen him on March 12 or have information regarding his death.
Information can be provided to police by calling 105 and quoting file number 200413/6113 or contacting the Op Kane investigation team directly on 021 191 0879.
Crimestoppers can also be contacted anonymously on 0800 555 111.
Police today cordoned off the Casey Ave property which will now be forensically examined. Photo / Nikki Preston
