A police investigation into a missing 49-year-old builder has enlisted the help of an international expert as it reaches the 200th day since he disappeared.
Michael McGrath was last seen at his Checketts Avenue home in Christchurch on May 21.
Detective Inspector Darryl Sweeney says police have collected 300 items for forensic assessment after spending 6000 hours searching the Kate Valley Landfill for clues.
Mr McGrath's house has also been re-examined in the past few weeks and an international expert has created a geographic profile for where his body could be located.
"I am confident that this investigation is advancing and our team remains dedicated to locating Michael and providing answers for his family," says Detective Inspector Sweeney.
Thousands of leaflets had been distributed across Christchurch and police were reviewing CCTV footage in the area.
Key interviews with people connected to this investigation will occur again in the next fortnight.