Police say an international expert has helped pinpoint new areas in the search for Christchurch man Michael McGrath, who has been missing for more than two months.
Mr McGrath, a 49-year-old builder, was last seen at his home in Halswell on May 21 and his disappearance has been described as out of character.
Police say they've now uncovered unspecified "areas of interest in the greater Christchurch region" thanks to outside help.
"In recent weeks police have been consulting with an international expert in locating evidence," Detective Inspector Darryl Sweeney said.
"That expertise will be overlaid with information gained during the investigation and from the public."
Specialist search teams would join civilian groups in searching the new area.
The search for Mr McGrath has included a search of the Kate Valley refuse centre by more than 20 police staff over four weeks, and dive searches of local waterways.