Widow helping police with enquiries after wealthy farmer's death three months ago

Police have arrested the widow of NSW sheep farmer Mathew Dunbar in relation to his suspicious death although no charges have been laid.

Mathew Dunbar, 42, was found dead at his Walcha home, in the Northern Tablelands in the early hours of August 2 after police and ambulance officers were called to the scene.

Homicide squad detectives started investigating a few days later.

Now his widow, Natasha Crossman, is helping police with their inquiries after the death was initially said to be a suicide.

Mr Dunbar with Ms Crossman. Source: Supplied

"A 42-year-old woman is assisting police at Tamworth police station," a NSW Police spokeswoman said.

News Corp Australia reports police found Mr Dunbar connected to a helium gas tank at his property Pandora, and that Ms Crossman's ex-husband, Colin Crossman, was one of the first paramedics on the scene.

However, there is no suggestion he had anything to do with Mr Dunbar’s death.

On Saturday, Ms Crossman was driven to Tamworth Police Station, 100km east of the Walcha property, where she remains in custody. She maintains Mr Dunbar took his own life.

The Daily Telegraph reports Ms Crossman said the investigation had finished and that her partner had taken his own life after previous attempts.

The Daily Telegraph reports Ms Crossman said the investigation had finished and that her partner had taken his own life after previous attempts.

• Top neurosurgeon reveals why he left his own charity

• WATCH: Shocking moment car slams into truck in fierce outback dust storm

• 'Freak outcome': Man in induced coma after lightning strike

“I was there — I know he killed himself. But I mean [the police] have to investigate,” she said.

Ms Crossman said she is dealing with post-traumatic stress because she “was the one who found him”.

She said Mr Dunbar was upset about having a limp as a result of a recent leg infection. He was also depressed the injury would affect his work on the farm.

But Mr Dunbar’s estranged mother Janet Dunbar told The Telegraph her son would not have committed suicide because he never struck her as “that sort of person”. Despite falling out with him, she said he wanted a family.

NSW Police were contacted for comment but a spokesperson could not confirm if charges would be laid on Ms Crossman.