Christchurch search continues for missing man Michael McGrath

Search and rescue teams in Christchurch have been helped by members of the public in an intensive grid search for missing man Michael McGrath.

With Mr McGrath now missing for 13 days, the search team of 30 are combing paddocks, creeks and even suburban properties. It is careful, painstaking work.

Six teams, including police, volunteers and a dog, spread out across the search zone in Haswell, on the outskirts of Christchurch.

It follows a public plea for information from police, who on Friday confirmed they're still hoping to find the 49-year-old builder alive.

"I am asking people to think back almost two weeks ago now to Sunday, the 21st of May, and forward of that day," says Christchurch police Detective Inspector Darryl Sweeney.

Saturday's search centred on a home in Haswell, which has become ground zero for the inquiry.

Police are also appealing for sightings of Mr McGrath's Subaru Legacy and mountain bike.

Police say Mr McGrath could have been wearing blue jeans, a black t-shirt with red lettering on the side, as well as Hi-Tech branded shoes and a grey-and-white crew-neck jersey.

Police are yet to reveal if the search and rescue operation uncovered any clues, but they continue to stress this is still a missing person's inquiry, leaving Mr McGrath's brother, Simon, holding on to hope he will be found alive.

"His disappearance is completely out of character, and his family are completely concerned," Simon McGrath says.

As time ticks on it will likely be the public's help that leads to a breakthrough.