Western Australian woman Janette Dowsett told the inquest examining Ms Butterworth's presumed homicide 46 years ago that her ex-husband, convicted rapist John Lonergan, was a ''very violent man''.

Lonergan, who died in 2012, has been named as suspect in the case due to his modus operandi of picking up girls from bus stops and sexually assaulting them.

Mrs Dowsett told Coroner Simon Cooper on Wednesday that she left her husband in 1970 and had been told was by doctors he was ''a man without conscience''.

Mrs Dowsett said she suspected Lonergan was responsible for Ms Butterworth's disappearance, and when she asked him if he was responsible he began to hysterically cry.

''He said believe me, I didn't,'' Mrs Dowsett said.

She told the inquest she noticed a ''funny smell'' around the house after Ms Butterworth vanished, and that Lonergan began laying concrete in the yard.

Mrs Dowsett said she noticed ''black sticky stuff'' in the lounge room that she suspected could have been remnants of the black coat Ms Butterworth was wearing.

She said she found a woman's compact near Lonergan's incinerator.

During their marriage she said Lonergan mutilated the family cat, and later shot her dog.

Mrs Dowsett said on several occasions she thought Lonergan was going to kill her, and had threatened to if she left him.

Counsel assisting the coroner Simon Nicholson asked Mrs Dowsett if she thought she had exaggerated her observations over the years, to which she replied: "No, I don't think so''.

Ms Butterworth vanished from a Claremont bus stop in August 1969.

The main person of interest in the case is convicted murderer Geoffrey Charles Hunt.

On Monday the inquest will hear evidence from Mr Hunt's brothers.