Michael McGrath search moves to rubbish dump

Police have enlisted help from the Army as the search for missing Christchurch builder Michael McGrath today moves to a Canterbury dump.

Police and family have grave concerns for McGrath, 49, who was last seen at his Checketts Ave home in the suburb of Halswell on May 21.

He was reported missing two days later.

A search of the Kate Valley landfill site at Waipara in North Canterbury has started today.

Police have help from 20 members of the NZ Army based at Burnham Military Camp near Christchurch.

The search is expected to take at least two weeks.

It is the latest in a number of land, water and property searches as part of the ongoing detailed investigation into McGrath's out-of-character disappearance.

"Searching the landfill will obviously be a challenging task, and we are fortunate to have the personnel and logistical expertise of the NZ Army available to us," said Detective Inspector Darryl Sweeney, who is heading the inquiry.

The Police National Dive Squad found little of interest during searches in the Halswell area last week.

Police say that Christchurch Men's Prison Corrections officer David Benbow is "a person of interest who needs to be eliminated from the inquiry".

The prison guard's rural property just a few kilometres from McGrath's house has been the focus of a massive police investigation.

McGrath's brother, Simon McGrath, appealed to the public for help during a police press conference this month.

He's also posted a heartfelt message to his brother on Facebook."Bro I think of you out there somewhere and I am sitting here without a clue. I hope that you return to me someday. For as long as I live my thoughts will be always with you."

Anyone with information can contact Christchurch Central Police Station on (03) 363 7400 ir anonymously call Crimestoppers on 0800 555 111.