The brother of missing Christchurch man Michael McGrath says he's never given up on the search

It's been four years since the carpenter vanished from his Halswell home.

McGrath's childhood friend David Benbow is charged with his murder and is awaiting trial.

Simon has spoken in detail to the NZ Herald over the devastation his brother's disappearance left behind.

He says he knows Michael is still out there somewhere.

In the last few years he's searched 200 square kilometres of coastal Lake Ellesmere - and picked over rural parts of Canterbury.