Police focused on finding missing Christchurch man Michael McGrath alive

Police searching for a missing Christchurch man say they're focused on finding him alive, but have "serious concerns" for his wellbeing.

Michael McGrath, 49, hasn't been seen since May 21.

Detective Inspector Darryl Sweeney says a dedicated team of investigators are continuing to search for the Halswell builder.

Three properties and three motor vehicles are under forensic investigation.

Mr Sweeney confirmed they have been speaking to a "person of interest" over the last couple of days, and says they're particularly interested in Mr McGrath's movements on May 20, 21 & 22.

They're now appealing to the public for and sightings of Mr McGrath or his car, a 1994 blue Subaru Legacy station wagon, in Halswell on these days.

Information can be passed on at your local Police station, or anonymously through Crimestoppers on 0800 555 111.