A 69-year-old man has been found guilty of assisting his wife’s suicide to claim on her $1.4m life insurance.

On Nov. 30, 2014, police found the lifeless body of Jennifer Morant, 56, in the back seat of her car with the doors closed and a note saying, "please don't resuscitate me." A petrol generator was also found in the boot.

Graham Robert Morant, 69, was convicted by a Brisbane Supreme Court jury of assisting and counselling his wife to take her own life in order to claim the $1.4 million payout from Mrs Morant’s three life insurance policies, for which he was sole beneficiary, ABC reported.

Morant told his wife, who suffered from chronic back pain, depression, and anxiety, that the insurance money would be used to build a religious commune.

Morant initially denied involvement in his wife’s suicide until he learnt of CCTV footage of his visit to the hardware store.

"Slowly, very slowly, over the course of the next hour the accused explained he did assist his wife in her suicide," Crown prosecutor Michael Lebanese told the court.

During the trial, Judy Dent, Mrs Morant’s best friend, testified that Mrs Morant made it clear her husband wanted the insurance money.

Dent said that a week before Mrs Morant’s her death, she told her “I have to do it” and “I have to kill myself and Graham will be helping me.”

Morant was refused bail until his sentencing, which is set to take place on Oct. 19 due to the complexity of the case, ABC said.