Lee Hall spoke of how her heart lurched when she heard her son Brett was missing from his Wanganui home.
At a press conference, Mrs Hall described his disappearance from his lifestyle block, 30km up Wanganui's River Rd, as out of character.
Brett Hall, 47, was reported missing more than a week ago and police are treating the Palmerston North man's disappearance as a homicide.
At the conference they joined his mother in appealing for help from his friends and associates who were aware of his "chequered past".
Mr Hall was last seen on May 29 at his lifestyle block. Eight days of searching have found no trace of the man who had previously come to the attention of police, but not in the past two years, said Detective Senior Sergeant David Kirby.
Yesterday neighbour John Thurlow said he first knew something was wrong when he came across a live possum in a trap on Mr Hall's land.
"Under normal circumstances, anyone around here would dispatch it as soon as it was caught in the trap. But after a whole day, it was still caught in the trap and nobody had done anything about it and he wasn't that sort of person," Mr Thurlow said.
Mr Hall's mother, accompanied by his son Damian, said Brett Hall, also known as Jimmy, was a quiet, private man who loved his family and idolised his two grandchildren.
She said he had a love of the outdoors, particularly hunting and fishing, and was extremely fit.
Mrs Hall said his disappearance "is doing my head in ... not knowing is just tearing us apart".
"If you've spoken to him, please come forward and speak to the police."
Mr Hall is described as European, 1.82m tall and of medium build.
- additional reporting: Amelia WadeBy Amelia Wade Email Amelia