"It was abnormal not the usual car or fire smell, very unusual ... it certainly didn't smell like bushfire or trees or grass," Alison Stuart told the NSW Supreme Court.

"It was something that I had never smelled before."

She had been watching Ready Steady Cook when continuous screams rang out in her Rouse Hill neighbourhood on December 2, 2013.

She was giving evidence on Thursday via video link in the trial of 42-year-old Kulwinder Singh who has pleaded not guilty to murdering his 32-year-old wife Parwinder Kaur.

Another neighbour Leesa Flanagan heard Singh utter the words "fire, fire," followed by, "I'm a good man, I didn't mean for this to happen".

She could see a burned woman lying on the grassy area outside the house while the man was sitting on some rocks being comforted by another neighbour.

Ms Flanagan said on Tuesday that he appeared distressed as his hands were moving rapidly and he was speaking very fast.

She had been outside in her backyard when she first heard the screams and soon became aware of a petrol smell that reminded her of the "Parramatta speedway".

Someone yelled for her to get blankets but with not enough time she dialled triple zero instead.

The Crown submits Singh poured petrol on his wife before setting her alight after arguing over money and financial issues.

But Singh's barrister, Margaret Cunneen SC, said Parwinder Kaur poured the petrol and set herself on fire to create a "drama", confident the blaze would be put out.

"There is simply no forensic evidence that supports the crown case," she said in her opening address.

Ten of her fingerprints were found on the petrol tin, but none of her husband's and only her fingerprint was found on the lighter as well as only her DNA.

On a visit to India, Singh allegedly told his sister-in-law that if his wife wanted a divorce, he would not agree, saying "we kill people and nobody can find out".

The trial continues before Justice Natalie Adams.

Australian Associated Press